Rangers manager Walter Smith insists he will not rush back Barry Ferguson even if Kevin Thomson faces a lengthy injury lay-off.
Thomson was stretchered off late on in Sunday's 4-0 win at Kilmarnock after an impressive display in the Gers' midfield.
The Scotland international was writhing in agony after appearing to twist his knee in a challenge with Killie's David Fernandez.
Thomson is almost certain to miss Wednesday's league game at Motherwell, seemingly paving the way for skipper Barry Ferguson to make his first start since the Scottish Cup final in May.
Ferguson came through his third substitute appearance unscathed at Rugby Park after recovering from ankle surgery, but Smith is adamant the talismanic midfielder will only return to his starting line-up when he is 100% fit.
"Barry will come back into the team when he is ready," he said. "We will be careful with him to make sure that he's ready. It doesn't take away any dilemma for me.
"Kevin Thomson was the best player on the pitch today, he has been doing extremely well for us in recent weeks, and we wouldn't want to lose him.
"Hopefully when things settle down it might not be as bad as we think at the moment.
"Barry wasn't due back until November 21 so he has been a little bit ahead of schedule and he still needs a few games.
"We have Maurice Edu as well and Steven Davis can play in there so we still
have other players who can play in that position."
Smith's medical team must wait for the swelling to subside before discovering the full extent of Thomson's injury.
"He's twisted his knee and there is a fair bit of swelling on it but it's too early for anyone to give a full diagnosis," Smith added.
"It will be a few days before we'll know if there is any damage."