Lionel Messi turns 32: But are his best moments already behind him?

Argentinian magician Lionel Messi turns 32 on Monday, meaning that he has now spent half of his life playing for Catalan giants Barcelona. But is the maestro's influence waning as his career extends towards its conclusion?

Messi has plundered more than 600 goals during his time at the Camp Nou, including another impressive tally of 51 goals in 50 games last campaign. But as the years wear on both Barcelona and Messi must begin to face the inevitability that, yes, one day his influence will diminish.

Of course, this won't happen overnight. Messi is clearly still as potent a goalscoring threat as he has been throughout his career, even as the supporting cast around him changes as first Xavi and Iniesta, then Neymar, departed for pastures new.

The one constant in the Barcelona forward line for the best part of two decades, Messi is surely at a part of his career now where his best days are already recorded in the history books.

His chief rival for world football's leading individual honors, Cristiano Ronaldo, has extended his playing career well into his mid-30's thanks to an almost inhuman fitness schedule designed to maintain him at his absolute best for as long as humanly possible.

The Argentine has never been Ronaldo's equal when it comes to their physical attributes, so perhaps football fans must acquaint themselves with the stark possibility that Messi's greatness is now at the business end of a very finite career spectrum.

Diego Maradona, the man to whom Messi is most often compared, is remembered for his heyday in the 1980's and not for the self-destruction and drug test failures which followed.

Pele, too, is remembered in the most revered of tones but his abject spell at NY Cosmos towards the end of his career is forgotten.

There are more: George Best, Brazil's Ronaldo and even Wayne Rooney (whose career is in its latter stages in Major League Soccer) have contended with the inevitable sports law of diminishing returns.

And now Messi must also stare inevitability down.

If Messi's epilogue is to be written as such, it will not come immediately. He is the type of player whose status bypasses that of club rivalry (perhaps with the sole exception of Real Madrid supporters), the type of figure universally loved and feared by the global football community.

Messi's lack of international success with Argentina is the sole disappointment on a career ledger which lists practically every achievement available in the club game. Messi's international status suggests that he will be available for selection for the 2022 World Cup, where he will be 35 - a year older than Maradona's calamitous World Cup swan song in 1994.

Xavi says that he expects Messi to play at the top level until he is 40, something which would require him to drop further back into midfield and trade his role to be that of a creator. He has already started doing that recently with Barcelona, adjusting for a potential physical decline by placing himself in positions to make the most of his unparalleled football IQ.

As the candles continue to accumulate on Lionel Messi's birthday cake, it stands to reason that his goalscoring exploits will begin to suffer - but, if as Xavi suggests and he adjusts his game to deal with the rigors of age, the prospect of him becoming an Andrea Pirlo-like influence in the Barcelona midfield is a tantalizing one.