Rangers manager Steven Gerrard has revealed that Borna Barisic has yet to prove his fitness for the League Cup final, and other Rangers stars also have injury concerns.
Barisic has emerged as a key player for Rangers this season but a foot injury ruled him out of the midweek clash with Aberdeen and Gerrard is crossing his fingers that the Croatian left-back is available to face Celtic at Hampden on Sunday.
The manager's plans could be further hit with news that other players, one of whom is believed to Steven Davis, may not be available.
"Borna did a light session today," Gerrard said. "He did three-quarters of that. We're very hopeful.
"We've still got to do one more session tomorrow so Borna and a few more who were carrying knocks from Aberdeen will be given as late as possible to give themselves the best chance to make themselves available.
"It's important that they say to us, 'Yes I'm 100 per cent and ready' because it's going to be a tough challenge on Sunday against a good team.
"There is a possibility it could go further than the 90 minutes so the players need to prove to me in the session that they are ready and show me too.
"Borna needs to be ready to do himself justice and to find his best level. He has to think about the supporters and the team and not make a decision on ego."
Gerrard said that a training session on Saturday will be decisive for the players concerned.
"We've still got one session left," he said. "I'll give you that we've got one or two carrying knocks but that's normal coming off a tough game on Wednesday night.
"We will have everyone out there tomorrow morning trying to get through the last session. If that's the case I should have a fully fit group to pick from.
"I'll know more tomorrow. If the last session was today I'd definitely be saying we have one or two doubts but we've still got 48 hours before the game, there's more treatment to be given so I'd say I'm more hopeful sitting here right now.
"But that could go either way."