Arsenal manager Arsene Wenger knew Kim Kallstrom had a back injury when he signed the Sweden midfielder on loan on transfer deadline-day, but said it was too late to find anyone else.
Despite Arsenal's financial firepower, the 31-year-old midfielder was the only arrival in the January transfer window. Signed until the end of the season as injury cover, Kallstrom might not be fit until mid-March after arriving on Friday at Arsenal having injured his back earlier in the week while training with Spartak Moscow. If Kallstrom remains sidelined, Spartak will pay his wages for up to six weeks.
Wenger said on Sunday he considered aborting the deal for Kallstrom, who has made 108 appearances for Sweden. "I would not have signed him if we had two or three more days to do something, but it was Friday night at five o'clock, so it was (a case of) you (sign) nobody or you do it under these conditions," Wenger said Sunday. "I decided to do it because we might, because of the number of games we have now in February, we might need the players in March or April.
"There is a possibility (that he may not play) but as well there is the possibility that he scores us the winning goal that might be vitally important."
The injury, described by Wenger as a "micro-fracture," prevents Kallstrom from immediately providing cover for Mathieu Flamini, who has two games of a suspension remaining, and injured midfielders Jack Wilshere and Aaron Ramsey.
"Since the start of the season, all our central midfielders have missed a part of the season - whether it's Flamini, Wilshere, (Mikel) Arteta, (Alex Oxlade) Chamberlain or (Santi) Cazorla," Wenger said.
"All of them have had injuries and it can happen that a few of them miss the next part (of the season) together."
Arsenal are provisionally top of the Premier League after the injury-hit team beat Crystal Palace 2-0 on Sunday. Although Wenger spent nothing in January, he was pursuing targets, with a deal for Schalke attacking midfielder Julian Draxler collapsing.
"We are not against spending," Wenger said. "You have announced a lot of transfers in your papers that have not happened, in many places, that means it is not as easy as it looks, even with money, to buy the right players in that period."