Peterborough United boss Darren Ferguson has said an injury to Gabby Zakuani could cause defensive problems for his side's end-of-season run-in.
Zakuani was withdrawn with a back complaint in Tuesday's 2-0 loss to West Ham, leaving Shaun Brisley as Posh's only recognised centre-half.
The result keeps Posh nine points above the Championship drop zone.
"Craig Alcock can play there. I've got some kids I can throw in," Ferguson told BBC Radio Cambridgeshire.
"We tried to get one or two in [on loan] before the deadline. But it just wasn't going to happen."
He added: "When you're trying to get them in with a short time to go it's difficult because teams don't want to let go of players.
"And if they're really out of the picture I don't see why I should bring them into the club. We'll have to go with what we've got but I'm confident we'll get enough points to still be playing Championship football."
Zakuani, 25, has been sidelined by a string of injuries this season, most notably with an ongoing toe problem.
Ferguson says the centre-half's latest setback, which saw him come off after 62 minutes against the Hammers, makes him "doubtful" for Saturday's visit of Leicester City.
"It's nothing to do with his toe. It's his back and he's had a spasm," said the Scot.
"We missed him when he went off. We missed his leadership qualities. It was at a time when we needed to be organised and we started to lose our shape."