Rangers midfielder Ryan Jack could be out for two weeks with a calf injury he sustained in Sunday's 2-1 defeat to Hearts.
The Scotland international was replaced at half-time by Scott Arfield and is set to miss games against Hibernian, Kilmarnock and former club Aberdeen.
Jack has emerged as an integral player under boss Steven Gerrard as the Glasgow side have mounted a title challenge against rivals Celtic this season.
"Ryan has had a little recurrence of an injury in his calf," said assistant manager Gary McAllister.
"We're talking 10 days to two weeks out."
Skipper Tavernier close to comeback
However, McAllister is hopeful captain James Tavernier's return is fast approaching after the full-back missed the last three matches due to an appendix issue.
He added: "The word with James is he is a couple of weeks away. He is back on the grass now and he is a fit lad so he might get back quicker."
Jake Hastie recalled from Rotherham loan
Winger Jake Hastie has returned to Rangers midway through a season-long loan deal at Rotherham.
The 20-year-old scored in his first three appearances but has only started one of the Millers' last 12 games.
Reports claimed this week Rangers were looking to offload Jordan Jones and Brandon Barker to free up space for a new signing, with fellow wingers Jamie Murphy and Eros Grezda having already moved on this month.
On Jones and Barker, McAllister said: "They are two players that were brought here to try and make a difference, to try and make us better.
"All the coaching staff wanted those guys here. They are two players who we thought could influence games when it's very, very tight.
"Recently the pair of them have been injured and it's up to them to show the manager and the management group, they have got to do more to get in the team.
"If they show us in training, they will get an opportunity."