Paul Scholes is concerned that Wayne Rooney may be past his peak after playing too many games since his meteoric rise to prominence aged 16.
After scoring on his debut for Everton it was not long before Manchester United came calling and Rooney has been a regular at Old Trafford since 2004.
With a huge burden of expectation on his shoulders for both club and country, along with the sheer quantity of matches that he has played, Scholes is worried that the 28-year-old may have reached his peak earlier than expected, which could lead to an early retirement.
"Wayne was in the Everton team at 16 years of age, in 2003," the former United midfielder wrote in a blog for Paddy Power. "Since then he's played at Euro 2004, two World Cups, Premier League, and Champions League every year at United.
"There's a chance he's worn out.
"Wayne's peak may have been a lot younger than what we'd expect of footballers traditionally.
"Age 28 or 29 has been the normal 'peak'. With Wayne, it could have been when he scored 27 league goals in 2011-2012 when he was 26.
"Wayne might be a player who'd retire come 31 or 32, given the amount of football he's played."
Scholes also suggested Rooney would only cement his place as a world-class player if he performed at a World Cup finals.
Rooney has yet to score having played in two tournaments already, and his former team-mate insists it is time for him to shine on the world stage.
"If Wayne is going to be one of the best footballers in the world, this World Cup is where he has to produce," Scholes added. "His best attributes are his energy, desire, a will to win which is unbelievable – but, above all, his goals.
"He needs to use his energy more effectively now as he's a player who likes to be up front on his own and I don't think he's great with partnerships.
"I'm not saying Wayne needs to be dropped but if form doesn't get up to scratch in the warm-ups, or in the first game of the World Cup, it'll be interesting to see if the England management team has the balls to make that decision."
Roy Hodgson's England take on Italy, Uruguay and Costa Rica in Brazil.