United States goalkeeper Tim Howard may have to consider his international career if he is to play until he is 40, former Everton shot-stopper Nigel Martyn has told the Liverpool Echo.
Howard, 35, starred for his nation at the 2014 World Cup, in particular against Belgium when he made a string of fine saves only to suffer a 2-1 defeat in extra time.
The American signed a contract extension with Everton in April that ties him to Goodison Park until 2018, when he will be 39.
Martyn, who made 86 league appearances for the Toffees, believes Howard could play until he is 40, but feels the former Manchester United keeper may need to weigh up his international commitments.
"The international aspect is an interesting one with Tim," former England international Martyn said.
"Does he think he can do another four years and another World Cup? There is no reason why he can't but it will become more difficult and more tiring.
U.S. World Cup exit reaction:
- Jeff Carlisle: Reviewing Klinsmann's World Cup
- Roger Bennett: The future is bright
- Jason Davis: A tale of two strikers
- Chris Jones: Band of brothers go down fighting
- Doug McIntyre: Young players shine
- Landon Donovan: We need to keep developing
- Klinsmann Cam: Emotional ups and downs vs. Belgium
- Pablo S. Torre: Hey, America, where are you going?
"But if he has got the desire then why not? I had the opportunity to get back in the England frame in 2004 but felt that going as second or third choice for a major tournament would've been detrimental to my career at Everton.
"If Tim wants to carry on playing club football at that level then he may have to step away from the international scene."
Martyn added: "How long Tim can keep playing is down to his form and if he stays clear of injury. Also how he feels mentally is important as well.
"It is slightly easier for an English guy to stay in England and carry on playing.
"I don't know whether Tim would want to finish his career back home and play a couple of seasons in the MLS. But as long as he wants to do it and stays clear of injury then Tim can easily to play until he is 39 or 40.
"It is a season by season or even a six-month by six-month thing."