Ben Foster has admitted he is getting disheartened with life at Manchester United.

Although he started the season as first choice following Edwin van der Sar's finger injury, a couple of high-profile mistakes coupled with the veteran Dutchman's return to action have forced Foster out of the side.

While he was in goal for the Carling Cup tie at Barnsley last month, Foster has not even been on the bench for the vast majority of United games recently.

Yet he has still been England's goalkeeper for the last two games.

The first one of those, against Belarus in the final World Cup qualifier, was somewhat fortuitous because Robert Green was suspended.

He was in on merit for the single goal defeat to Brazil in Qatar and appears well placed to earn a place in Fabio Capello's squad for next summer's World Cup.

The situation just makes Foster even more confused, as he tries to re-establish himself again at Old Trafford knowing Van der Sar remains firmly positioned as Sir Alex Ferguson's number one.

"It's a weird one," he said.

"I am third choice for Manchester United at the moment yet I am playing for my country.

"It is very disheartening not even be on the bench at United.

"Edwin is one of the best keepers in the world. I can't really go knocking on the manager's door and say he is not doing his job because he is."

Foster has previously stated his desire to remain at Old Trafford so he can find out for certain whether he has what it takes to be a first-choice goalkeeper at one of Europe's leading clubs.

Many wise judges think he can. Indeed, during United's pre-season tour of the Far East, Ferguson stated his belief that Foster would go to South Africa as England's number one and reaffirmed an intention to give him as much match practice as possible.

Unfortunately, Foster's mistakes, while limited, have been costly.

A blunder against Chelsea in the Community Shield was quickly forgotten. Less easy to dismiss were the mistakes he made in the Manchester derby, first in losing the ball to Carlos Tevez near his own box to gift the Blues their first leveller, then going down far too easily and effectively providing Craig Bellamy with a tap-in for City's third.

Michael Owen's stoppage time winner ensured United still won and it took another late goal, this time a deflected effort by Patrice Evra, to salvage a point for the Red Devils after Foster had been brushed aside in an aerial duel with Kenwyne Jones for Sunderland's second goal.

"I thought I started off well but then there was a period of two or three games where I made a few mistakes," he said.

"But they were the only ones I made really and I was disappointed to find myself out of the team."

It would take a brave man to confront Ferguson about the situation and Foster has no intention of doing that just yet.

He is thankful to Fabio Capello for sticking with him though, just as he breathed a sigh of relief when his second-half challenge on Nilmar brought Brazil a penalty without the usual automatic red card.

"I definitely thought I was gone," he said.

"It was exactly what happened to Robert Green in the Ukraine and he went. The referee probably left it because it was a friendly.

"I was happy to stay on the pitch because I was really grateful for the chance.

"It was a bit out of the blue but I have done really well in training this week and thankfully, the boss stuck with me.

"It is everything for a footballer to go to the World Cup but I can't go saying 'I want to leave' or anything like that.

"I have just got to see what happens."