Edwin van der Sar will miss Manchester United's UEFA Champions League game against Roma on Tuesday with a toe injury.
The Dutch international sustained the problem during the first-half of United's 1-0 victory over Birmingham at St Andrews, with Cristiano Ronaldo scoring the only goal of the game.
After appearing to catch his foot in the turf in the 23rd minute, Van der Sar continued after treatment, but was replaced at the interval by Tomasz Kuszczak, who will deputise again at Old Trafford in midweek.
United boss Sir Alex Ferguson said: "Van Der Sar has damaged his toe. To what extent, we are not sure. We will send him for a scan but he will definitely be out on Tuesday.
"It is a worry to lose a man of his experience, but Tomasz is very able and we are pleased we've got someone as good as him."
Both goalkeepers were kept busy by Birmingham and Ferguson admitted: "On reflection, that is the best side we have played this season.
"In the first half we were lucky, although we did carve out a few chances of our own. I couldn't wait to get in to half-time.
"Birmingham were very athletic, very aggressive, very quick about the pitch and even at 1-0 I was still praying we would get through the match.
"We had opportunities but Birmingham, in the first half, had even better ones."
Ferguson was full of praise for Ronaldo, who scored his first league goal of the campaign on his 100th Premier League start.
He said: "Ronaldo was sensational again. The boy is so talented. His capabilities are unending.
"The goal might have come from a mistake but his composure was excellent."