Given Fabio Capello's stated preference not to pick players for England who struggle to get regular football at club level, Foster was genuinely surprised to be called up for Saturday's friendly with Slovakia.
The 25-year-old has not appeared for United since his man-of-the-match performance in front of Capello during the Carling Cup final win over Spurs almost four weeks ago.
So, should he win a second cap this weekend, adding to the first he won against Spain under Steve McClaren in February 2007, it would represent a remarkable achievement.
However, Foster is realistic enough to admit that to have any chance of boarding the plane to South Africa in 2010, he cannot still be appearing sporadically for United as back up to Edwin van der Sar.
Easing out the veteran Dutchman is a task which has proved too difficult for Foster so far. But he has vowed to renew his efforts next season in order to achieve a dream double.
"The biggest club in the world against the biggest competition in the world, that is the dilemma," he said.
"Playing for England is a hugely important thing but I am also at the biggest club in the world. I will only get one chance at that and I don't want to give it up.
"I have to come back next season and get into the manager's face as much as I can. I want to be playing and I want to get into the World Cup squad next season."
Given David James is battling at the wrong end of the table with Portsmouth, fellow squad member Robert Green is at a mid-table club in West Ham and other plausible candidates such as Paul Robinson, Scott Carson and Joe Hart are either fighting relegation or unable to command a starting spot at their clubs, it could be argued if Foster can edge past Van der Sar in the next 18 months, an England place will be secured automatically.
"Possibly that is true," he said.
"Playing for United does not guarantee you anything but it would certainly make it easier.
"I am up for the job but it is proving certainly tough enough to get into the United squad at the moment."
As Capello has pledged to make his maximum six substitutions on Saturday, Foster has a decent chance of being involved, even if Green, who was part of the squad beaten by Spain last month, has more of a claim.
Capello also has to solve the conundrum regarding Steven Gerrard's best position and where, if the answer is behind a main striker as has proved the case at Liverpool, that leaves Wayne Rooney.
Certainly there is no sense the loss in Seville - from which Gerrard, Rooney and Rio Ferdinand were all absent - has punctured public backing of the Three Lions, with just 8,000 tickets remaining to be sold for Slovakia, hardly the most attractive opposition.
In some senses, just being part of an England squad again is cause for celebration as far as Foster is concerned.
While his struggles to get a game at Old Trafford are well documented, it also has to be remembered that in the intervening two years since his last call-up, the former Stoke keeper has ruptured cruciate knee ligaments, broken a thumb and twisted an ankle on the eve of departure for the Club World Cup.
It is a succession of setbacks which have at least allowed Foster to adopt a more philosophical approach to his career.
"When you have so many injuries in such a short space of time, it teaches you to sit back and realise how fortunate you are when you can play regularly," he said.
"I have had bad times. Hopefully I am back on the up again now."
Maintaining that positive approach is one of the reasons why Foster was so happy to get the England call, a reward, as he sees it, for the more professional focus he has adopted.
"I have changed my whole life, with the things that I eat and things that I do," he revealed.
"I do a lot more work in the gym and I just try to calm it down and focus on going out on to the training pitch, doing my best and then take the same approach into matches as and when I get the chance.
"It certainly feels good to get that little bit of recognition."