Birmingham winger Jean Beausejour has been ruled out of the clash with Arsenal on October 16.
The Chile international winger, who joined Blues from Mexican side Club America in a £3.3m deal in the summer, has injured his knee ligaments.
And manager Alex McLeish admits there was always a danger that an injury could happen due to Beausejour’s late arrival on transfer deadline day.
Blues boss McLeish said: “He came to us half-fit, that’s part of the problem when you sign players at the end of the transfer window.
“We have to make sure we don’t take any unnecessary with him.”
Beausejour is yet to start a Premier League game for the St Andrew’s club but gave a glimpse of his ability by setting up two goals in the Carling Cup victory over MK Dons.