It's a fate that every great player hopes to avoid: decline and irrelevance.
With squads shifting and football evolving so quickly, even those who hit the highest of heights often have trouble maintaining their level at the top. Sometimes it's a move to a new club. Sometimes it's a devastating injury. And sometimes, it's a manager who just doesn't believe in a player's ability to contribute any longer.
Let's have a look at some of world football's erstwhile top players who find themselves at various points on the downward trajectory of their careers.
Barcelona's former golden boy hasn't had the best of times since his glory days at the Camp Nou.
Ronaldinho was an absolute sensation at Barcelona, lighting up world football with his audacious passes and quick dribbling. He played with a joy and character that is rarely matched in today's competitive game, but achieved incredible results in the process.
Unfortunately, Ronaldinho couldn't keep up his legendary performances in the Blaugrana shirt, and his decline began in his last season at the Camp Nou. As many of the Rijkaard era players made way for younger Masia products, Ronaldinho looked to reestablish himself at Milan.
Despite the extraordinary anticipation of his arrival there, the move was, by and large, a disappointment.
He had a good spell in the second half of the 2009-10 campaign, but the Brazilian was never able to capture the magical form that made him the best in the world, and after failing to score in the first half of the following season, he moved back to Brazilian football with Flamengo.
After quitting Flamengo in June following a pay dispute, Ronaldinho has been ascendant at his new club, Atletico Mineiro. Whether he can continue his renaissance in Brazilian football remains to be seen, but his prospects for a grand reappearance at next summer's World Cup took a serious blow with his recent exclusion from Brazil's Confederations Cup squad.
Let's hope that Ronaldinho—a true phenomenon when he's in the mood—will once again find his form on the international stage. But given his recent career troubles, that hope seems rather faint.
Ronaldinho's Brazilian teammate Kaka hit the same dizzying highs at the peak of his career, as well as the same lackluster lows in recent years.
Another former Ballon d'Or winner, Kaka has found it difficult to live with the pace of the competition for attacking roles at Madrid, most often losing out to Ozil, di Maria, and of course, Ronaldo for the three attacking roles behind the striker.
Only 31, Kaka is another player who—one would think—could have made his trade elsewhere and been considerably more productive. But the once-renowned playmaker has rather been content to languish at Madrid the past four seasons.
Perhaps, there is an out for Kaka after his disappointing spell. With summer transfers on the horizon, hope springs eternal for a top European destination. After so long out of the limelight, though, it may be difficult to find the form that made him the world's best.
It seems a distant memory, but it was only a few short years ago that Fernando Torres was one of Europe's most feared strikers.
After a several-season-long adjustment period, Torres has consistently failed to impress at Chelsea and has managed to play himself out of the running for a Spanish national team place in the process.
With the seasons drifting by at an alarming rate, how long will Torres remain at Chelsea in his attempt to regain top form?
Certainly, it's not too late for the striker—still only 29—to turn things around again. But he may need a change of scenery to get the job done.
Elsewhere in the Premier League, Manchester United have a slightly more predictable decline on their hands with both their centre-halfs on the wrong side of 30 and not getting any younger.
At 31 and 34, respectively, Vidic and Ferdinand have struggled in recent seasons to maintain their fitness, with Jonny Evans, Chris Smalling and Phil Jones increasingly being called upon to fill in.
It's been a steady and somewhat slow decline for one of the best central defense pairings in modern English football, but one that seems unlikely to reverse.
Speaking of aging centre-halfs, Carles Puyol hasn't had the best of seasons at Barcelona.
Captain since 2004, Puyol was a crucial factor in Barca's success throughout the Rijkaard and Guardiola eras. He also played a pivotal role in defense for the first of Spain's three international triumphs, in 2008 and 2010.
But this season has seen Puyol struggle to stay fit and stay up to speed against quick counterattacking offenses that increasingly were Barcelona's downfall.
Barcelona supporters will find it hard to forget Puyol's slip while trying to defend Angel di Maria in the second leg of the Blaugrana's Copa del Rey demise. As di Maria sped past Puyol and left him on the ground, the Camp Nou faithful were reminded of Puyol's age and vulnerabilities.
With Barcelona on the hunt for centre-half reinforcements over the summer, Puyol will likely be playing a more limited role next season. He's had a phenomenal career at Barcelona, but his best days are surely behind him.