Rangers boss Giovanni Van Bronckhorst is waiting to discover more about the nature and severity of Ryan Jack’s latest injury.
The midfielder made three substitute appearances recently after coming back from a calf problem which required surgery and which had kept him out since February.
Van Bronckhorst had hoped to give the 29-year-old more game time in the Europa League dead rubber at Lyon but the Scotland international pulled up in the final training session and will miss out on the trip to Tynecastle to play Hearts in the cinch Premiership on Sunday.
The Dutchman said: “I don’t know if it is the same injury.
“The last training session before Lyon, at the end of the session he went off the pitch with a problem so we are still diagnosing the problem and once we know more we can tell what injury he has.
“But he won’t be available for Sunday and hopefully he will join us soon, because he is working hard.
“Of course he didn’t have much game time in the last months through injury so for him personally it is not a good moment and also for us as a club because we don’t have Ryan Jack available for the games.”
After a creditable 1-1 draw with Group A winners Lyon that denied the French club a clean sweep of six group wins, Van Bronckhorst will prepare the league leaders for the challenge of Tynecastle against the third-placed Jambos, who snatched a 1-1 draw at Ibrox in October.
“We approach it like we always do against every opponent, watch a lot of footage of the team, prepare the team well in having the ball and also defending,” said the former Rangers midfielder, who revealed that striker Kemar Roofe is a doubt and will be assessed.
“We expect a very difficult game but I am sure my players will be prepared to face this challenge.
“Hearts’ preparations will be different to those for Livingston or Lyon so my players have to be really sharp in the team meetings and training sessions to be ready for the game and execute the game plan.
“We have to have a good overall perormance and be at the top of our game to have a good result on Sunday.”