Foster: Man Utd pals ripped into me over Malaysia gaffe
"Coming on in a game is always a bit more difficult for goalkeepers than starting but that was particularly disappointing," said Foster, who had replaced Edwin van der Sar at the interval.
"I got a bit of stick from the lads that's for sure.
"It was just one of those things. I wasn't paying enough attention and took my eye off the ball.
"I have to make sure that kind of thing doesn't happen again."