Kilderry first came onto McCormack's radar at just seven years of age.
“I was always around the tennis, and funny, in 1981 Bjorn Borg and John McEnroe came to Perth to play … my dad took me down to watch and I jumped on the court and had a hit with Bjorn Borg and his coach.
“His manager was there from IMG, who saw me play tennis at the age of seven, and sent a telegram to Mark McCormack, the founder of IMG and said 'I’ve discovered our next superstar, we’ve got to sign this kid!', which in 1981 was probably quite humorous, these days they'd sign that seven-year-old or eight-year-old!" Kilderry said.
"I got to play with Borg and then IMG did a few things for me and got me some sponsors and rackets and things like that."
A few years later, while Paul’s father was coaching internationally, he was able to meet McCormack in person, who had not forgotten the young star.
“He had an amazing memory and said 'oh is this young boy from Perth still playing tennis?' And I was at the time the national 14 and under champion, so my father said 'oh that's my son'!" Kilderry said.
“Mark was coming to Perth in 1987 for America's Cup and came down and watched me play, and offered my father a job to come work for him in America, and me a scholarship to go to the Nick Bollettieri Tennis Academy as a fourteen-year-old, so the whole family packed up and moved to Florida.”
Following his professional tennis career and a stint in coaching, Kilderry took on the task of heading up athlete management for Tennis Australia.
It's unusual for a sport's governing body to play the role of an agent, but professional tennis players have a unique set of needs.
“At the time (over a decade ago) we had a lot of players who were having troubles with management, so we would invest a quarter of a million dollars a year into a young player and help their development and supply them with a coach and help their physio and do everything for them to help them become a pro,” Kilderry said.
“We had a few instances where managers were getting involved and the focus was very commercial rather than about development.
“We also had cases where players might have signed up to something because they needed help at a vulnerable time in their career, and basically signed the next ten years of their career away, paying back the prize money or however it may be.”
Kilderry's first client was female professional tennis player Casey Dellacqua, who was initially signed on a one-year deal for 10 percent of her commercial earnings, about half of what most traditional sports management firms would charge.
"So Casey, you may remember, she had a great Australian Open, and all of a sudden she was talking about Target in a press conference, and then we were able to do a deal with Target which was the first deal I ever did actually," Kilderry said.
"I went in there and sort of worked through it, and because Nike was sponsoring Casey at the time it was really interesting, and Target was great to work with.
"It was fantastic, Target had never sponsored an individual athlete like that before and it was a unique brand, but I did learn a lot and I was thankful."
Forced to rely on both their minds and their bodies, sports stars often prove to be fickle creatures.
And while plenty of elite athletes have found the key to consistency, sports history is riddled with temporary stars who at some point mysteriously lost their game.
In golf, for example, David Duval somehow went from best in the world to completely irrelevant in a matter of months.
And on the gridiron, running back Chris Johnson has experienced a similar decline of late, abruptly transforming from NFL elite into unwanted free agent.
Finally, in baseball, Dan Uggla has recently proven to be just as mercurial, struggling profoundly enough to warrant getting cut and let go by the Braves and Giants, respectively.
With these erratic athletes in mind, we've compiled a comprehensive list of "10 Sport Stars Who Inexplicably Lost Their Game."
Of course, athletes who can credit their demise to significant injuries, or any other obviously traumatic event, were not considered in this project. And it's also worth noting that we made an exception or two for athletes who eventually bounced back, but only after years of struggle and dismay.
That said, we've done our very best to highlight 10 figures who, for no good or obvious reasons, curiously morphed from sports superstars to athletic afterthoughts.
Golfer Anthony Kim never won a major, but the once-promising talent had three PGA Tour wins, Ryder and Presidents Cup appearances and a third-place Masters finish all before his 24th birthday.
As a result, Kim was heralded as one of golf's up-and-coming stars.
His career, however, didn't work out how anyone expected.
Following a fifth-place finish at the 2011 Open Championship, the Los Angeles native began a rapid and certain decline.
After making 10 or more cuts and at least $1 million in five consecutive tour seasons, Kim made just two cuts and $33,960 in 2012 and didn't play in a single tournament in either 2013 or 2014.
Now four years removed from competing on golf's grandest stage, Kim is out of the sport all together.
For nearly three solid years—between 1999 and 2001—John Rocker was one of the top closers in all of baseball.
Over that span, the hard-throwing, outspoken lefty recorded 85 saves and 260 strikeouts with a 3.23 ERA.
But for a man who was known for racing to the mound, his career fizzled out just as fast.
In 2002, while suiting up for Texas, the controversial pitcher managed to post just a single save while his ERA ballooned to 6.66. Then, in 2003, Rocker signed with Tampa Bay, but the Rays released him after just two games in which he posted an outlandish ERA of 9.00.
In the end, Rocker's last game in Tampa turned out to be his last in the majors, coming just two years after he dominated the sport.
Though she actually managed to bounce back in 2014, Ana Ivanovic had roughly a five-year stretch in which she inexplicably lost her game.
After winning the 2008 French Open championship and soaring all the way to world No. 1, the Serbian star abruptly fell into a rut.
In the year's final major—the 2008 U.S. Open—Ivanovic shockingly lost in just the second round, marking the earliest exit for a top-seeded player since all the way back in 1973.
Her slide continued in 2009, a year in which she dropped out of the top 20, plummeting all the way to 64th in the world in 2010.
In 2011, Ivanovic once again finished the year ranked outside the top 20 and then didn't win a single tournament in either 2012 or 2013.
Somehow, out of basically nowhere, she rediscovered her game in 2014, winning four tournaments during the season and finishing the year ranked No. 5. But nonetheless, for about five long years, Ana Ivanovic mysteriously lost her game.
From 2006 through 2011, Philadelphia's Ryan Howard hit 796 RBI to go along with 262 home runs! That's an average of 133 RBI and 44 homers per year while sporting a more-than-respectable .274 batting average.
During the remarkable six-year run, the phenomenal Phillie led all of baseball in homers twice and in RBI on three separate occasions, winning NL MVP (2006) and making three All-Star appearances along the way.
Then, suddenly, Howard lost his mojo.
In the last three-plus seasons—from 2012 until present day—the 2008 world champion has managed to hit 206 RBI with only 52 home runs, which equates to just 52 and 14 per 162 games, respectively.
Of course, some will blame his certain decline on a variety of nagging injuries—including a torn Achilles, which forced him to miss the beginning of 2012—but while they occurred in conjunction with Howard's glaring struggles, they certainly didn't cause them.
For added proof, simply look at the first baseman's numbers in 2015, now that he's officially "healthy" again: Howard has 12 RBI and 4 home runs with a .195 batting average and .247 on base percentage through 24 games.
And while his 2015 lack of production is an admittedly small sample size, it's been nearly four years since the 2005 Rookie of the Year last produced at a high level, which leads us to one obvious conclusion: Somewhere along the way, Ryan Howard lost his game!
For seven long seasons—from 1998-99 until 2004-05—Stephon Marbury was a legitimate NBA superstar.
While averaging 21.7 points, 8.3 assists and 1.3 steals per game during that span, the former No. 4 overall pick appeared in two All-Star games and on two All-NBA Third Team rosters.
The 2005-06 season, however, marked the end of his rise and the beginning of his demise.
At just 28 years of age—usually a prime year for an NBA star—Marbury's stats began to tumble, as he averaged just 15.9 points and 5.7 assists per game in three years with the Knicks.
To put his steady decline in perspective, consider this: By the end of his time in New York, the disgruntled and temperamental Marbury had lost his starting job to, wait for it, Chris Duhon!
Then, in 2008-09 with Boston, it all came to a head; the once-dynamic point guard managed just 3.8 points and 3.3 assists in 18 minutes of action per game.
And finally, in 2010, after four drama-filled, subpar seasons, Marbury said goodbye to the NBA for good.
In his first seven seasons in the league—all spent in Tennessee with the Titans—Albert Haynesworth established himself as arguably the most dominant defensive tackle in all the NFL.
In fact, Big Al was so good that, as a free agent in 2009, he demanded a seven-year, $100 million contract from the Washington Redskins!
That, however, was as good as it would get for Haynesworth.
Perhaps all the green went to the big man's head, because from 2009 on, the former first-round draft pick was an absolute disaster.
From failing fitness tests to publicly questioning scheme, Haynesworth was nothing more than a headache during his abbreviated two-year stint with the Redskins.
After a nightmare 2010 season—in which the high-priced signing registered just 13 tackles and 2.5 sacks in eight games—Washington traded Haynesworth to New England, where he lasted for less than four months.
Then, in 2012, Tampa Bay gave the two-time Pro Bowler one last shot, though he again came up short, lasting just seven games before getting released.
The Tampa debacle marked the end of the football road for Haynesworth, who went all the way from expensive and elite to worthless and unemployed in four unproductive years.
Though he experienced a momentary return to glory during Game 4 of the 2015 Eastern Conference Quarterfinals—scoring 35 points while also recording seven assists, five rebounds and three steals—Brooklyn point guard Deron Williams was dreadful in the other five first-round games, averaging just 7.2 points and 5.2 assists per contest.
More importantly, over the last four seasons, Williams has paled in comparison to his former self.
Since joining the Nets in 2011, the three-time All-Star has averaged middle-of-the-road numbers: 16.7 points and 7.3 assists per game.
Worse yet, the 30-year-old's skills have diminished even more over the last two seasons, during which he has averaged just 13.6 points and 6.4 assists.
Yet in his final four seasons with the Jazz—from 2007-08 to 2010-11—Williams was arguably the top point guard in the league, playing elite defense while putting up 19.2 points and 10.5 assists per contest!
And without any significant or career-altering injuries to account for, Williams' recent falloff is curious, to say the least.
At one point in time, Chris Johnson was among the best running backs in football.
Between 2008 and 2010, the NFL's 2009 Offensive Player of the Year rushed for 4,598 yards and 34 touchdowns, including an NFL-best 2,006 yards in just his second season in the league.
Fittingly, in each of those three years, Johnson made the Pro Bowl.
But with money rather than football on his mind, the East Carolina product struggled over the next three seasons, recording 3,367 rushing yards and just 16 total touchdowns.
And after making it to three Pro Bowls in his first three years, he made the prestigious roster zero times in the next three.
Not surprisingly, the rapid decline led to the Titans cutting the underachiever in 2013.
Unfortunately, a change in scenery did Johnson no good, as his 2014 debut with the Jets marked his worst season yet: The fickle back stumbled his way to just 663 rushing yards and one measly touchdown.
It seems somewhat hard to remember now, but from 1997 to 2001, David Duval was arguably the best golfer on planet Earth.
During the impressive five-year run, Duval won 13 PGA Tour events, including the 1997 Tour Championship, the 1999 Players Championship and the 2001 Open Championship.
And as a result of his impressive play, the Jacksonville, Florida, native rose all the way to No. 1 in the world!
After his 2001 Open Championship, however, Duval endured a tailspin of monumental proportions.
In 2002, the once-elite golfer fell all the way to 80th on the money list and, in 2003, tumbled even further—all the way to 211.
Duval toiled around golf long after his glory days—leaving the game on multiple occasions only to keep coming back—and only officially retired in 2014, but he failed to win a tournament or even regain relevance in any of his last 13 seasons!
Like everyone else on our notorious list, Dan Uggla's fall from grace was both ugly and abrupt.
In 2010, while suiting up for the Marlins, the hard-hitting second baseman took home the NL's Silver Slugger Award. And in 2006, 2008 and 2012, Uggla was a celebrated All-Star.
But unfortunately for Big Uggs, the 2012 season marked his last respectable campaign.
After averaging 89 RBI and 30 homers while batting .253 in his fist six seasons in the league, Uggla's production came to a screeching halt beginning in 2013.
Since then, the slumping athlete has averaged just 25 RBI and eight homers per year while sporting an ugly .173 batting average.
Worse yet, teams have recently given up on the former star, as he's been released by the Braves, designated for assignment by the Giants and offered nothing more than a minor league contract by the Washington Nationals.