Rangers manager Steven Gerrard says a late injury in training forced Connor Goldson to miss out on the trip to the Czech Republic.
The defender didn't fly out with the rest of the squad to face Sparta Prague, leaving the Ibrox club with a real selection dilemma.
Filip Helander is already out injured, while Nikola Katic is out on loan and Jack Simpson has not been included in the Europa League squad.
Gerrard had bemoaned the impact of Covid in his pre-mattch press conference but he revealed immediately pre-match that Goldson picked up a slight knock and should be back for the Hibs game at the weekend.
He said on BT Sport: "It was a curveball for sure because Connor's obviously trained and prepared but unfortunately he received a knock yesterday and we didn't want to take any risks.
"We have to prioritise Sunday really because it would have been a risk bringing him here tonight.
"We recruited Calvin Bassey for a couple of reasons: one because he could play left-back, but also that he could play centre-back.
"He actually played for Leicester's 23 squad at centre-back so we've got every confidence and belief that he can do a job for us.
"Having said that, this is a real tough test for all of us tonight."
