Alexis Sanchez move to Man United shows age is no longer a factor

The Alexis Sanchez transfer saga (2:48)

ESPN take a look back at the biggest transfer saga of the last six months as Alexis Sanchez joined Manchester United from Arsenal. (2:48)

Alexis Sanchez will be 33 when his four-and-a-half-year contract expires at Manchester United in June 2022, so it is safe to assume that Jose Mourinho and the Old Trafford hierarchy will expect the Chilean to make an instant, and prolonged, impact in the No. 7 shirt.

This is not a deal for the future. Where the likes of Anthony Martial, Luke Shaw and Paul Pogba were recruited by United for the long-term due to their age and potential, Sanchez has been signed for the here and now. At 29, his window of opportunity seems a relatively small one.

That United have done the deal at all, however, highlights a change of outlook at Old Trafford, and also within the game, when it comes to sign players closer to their 30th birthday than their 25th.

During David Gill's 10-year stewardship as United chief executive between 2003-2013, the club adhered to a policy of not signing outfield players over the age of 27.

Michael Owen, a 29-year-old free transfer from Newcastle in the summer of 2009, was an exception to the rule, but that deal was only done because United had missed out on Karim Benzema and David Villa when they attempted to replace Cristiano Ronaldo following his £80 million sale to Real Madrid.

Owen was also a relatively inexpensive addition to the payroll -- one which was mitigated by his commercial value to the club in markets such as the Far East -- Japan, in particular.

Gill's view, and it was one supported by Sir Alex Ferguson, was that footballers enjoy their best years between 23 and 27 and signing those beyond that age bracket made no financial sense. There was also a belief that players were hungrier and more likely to improve and contribute to success if their career path was still on an upward trajectory.

The £24m signing of the 29-year-old Robin van Persie from Arsenal in August 2012 was a game-changer for United, though, because Gill, encouraged by Ferguson, eventually sanctioned a move which went against all of his principles.

Van Persie, in the final year of his Arsenal contract, was expensive to sign, his £200,000-a-week wages threatened to be a long-term burden with little prospect of recouping the outlay and his best years were almost certainly behind him.

But the Dutch striker was an instant success, scoring 26 league goals which secured the Premier League title for United in 2012-13.

The gamble paid off, but Gill's wariness of signing players over 27 was perhaps justified by Van Persie proving less successful in his final two seasons at United before being sold for just £4.7m to Fenerbahce in the summer of 2015.

United, with Ed Woodward now pulling the financial strings, have further shed their caution in the transfer market post-Van Persie, however. And the move for Sanchez is an example of the club accepting that players no longer hit their peak in their mid-20s, but can enjoy their prime years in the late-20s and early-30s due to a variety of factors.

Gone are the days when clubs such as United would only sanction one-year contracts for players aged 30 and over due to concerns over their ability to last the pace. As little as 10 years ago, most 30-year-old footballers were one bad season away from the scrapheap, but improved fitness regimes, better coaching and conditioning and players largely eschewing alcohol to live a healthier lifestyle have seen many examples of stars continuing to shine well into their mid-30s.

Ryan Giggs, Xavi, Andres Iniesta, Andrea Pirlo, Paul Scholes, Steven Gerrard, Frank Lampard, to name a few, have helped change the landscape, but it is the ongoing success of Ronaldo and Lionel Messi which help explain why United have given the green light to a deal for Sanchez which could ultimately result in a financial outlay of up to £180m.

Ronaldo is 33 next month and is perhaps, only now, beginning to display the signs of ageing you would expect of a footballer who has spent 16 years playing at the highest level.

Messi, meanwhile, is 31 in June, but his age has not prevented Barcelona from securing him to a reported £500,000-a-week contract that will keep him at the Nou Camp until the end of the 2020-21 season, when he will be 34.

So has 30 become the new 25? Has superior fitness of players led to clubs rewriting their old rules to push the age barrier higher in order to splash out on what would, not so long ago, have been classed as veterans?

Eric Cantona was just 30 when he retired at Manchester United in 1997, with the Frenchman already beginning to display signs of slowing down before he called it a day.

But the game has changed to the extent that Manchester City and Paris Saint-Germain were prepared to battle it out to sign a 34-year-old Dani Alves from Juventus last summer.

United were prepared to pay Zlatan Ibrahimovic a huge salary 18 months ago when signing the then-34-year-old from PSG and they have made the same call now by trading Henrikh Mkhitaryan for Sanchez.

Indeed, such have been the improvements in the fitness of footballers in recent years, don't bank against Sanchez signing another contract at United to replace his current deal when it runs in in four-and-a-half years' time.