Lassana Coulibaly has been sent by Rangers to have a scan on his thigh after picking up an injury against St Mirren.
The combative midfielder has been a revelation since moving to Ibrox on loan from French side Angers this summer.
However, he missed the second-leg of the club's crucial Europa League third round qualifying tie with Maribor on Thursday.
Rangers earned a 0-0 drew which ensured passage to the play-off round without the Malian who has become a fans' favourite with his committed displays in the heart of the midfield.
The injury was picked up in the closing moments of the club's 2-0 Ladbrokes Premiership win over St Mirren on Sunday.
Rangers boss Steven Gerrard, whose side face Kilmarnock at Rugby Park in the Betfred Cup on Sunday, said: “We will find out more today. He has got a scan just to check the injury out as a precaution. We don’t think it’s a serious problem but he’s an important player for us so we want to check it out just to see if there is any damage in there.
“That was thrown upon us Thursday morning that he wasn’t available but I thought the lads handled it very, very well.”