Arsenal manager Arsene Wenger fears he will have no option but to quickly buy a new centre-back should Sebastien Squillaci's hamstring problem prove a serious injury.
The Gunners face the prospect of taking on Ipswich in their Carling Cup semi-final first leg at Portman Road on Wednesday night with only two recognised central defenders after Squillaci picked up a muscle strain during Saturday's 1-1 FA Cup third-round draw against Leeds.
Given Thomas Vermaelen is still not yet match fit, Wenger accepts that should Squillaci face a lengthy lay-off, the squad would need immediate cover for Laurent Koscielny and Johan Djourou.
"If we only have two centre-backs then that cannot work with the number of centre-backs we have," said Wenger, who has been linked with a move for Bolton's Gary Cahill.
"If Squillaci has a problem then we must quickly go out for a player."