Rangers suffered another selection blow ahead of two crucial matches after Todd Cantwell was ruled out of the trip to Spain.
The former Norwich midfielder will not feature in the Europa League decider against Real Betis on Thursday because of personal reasons.
Manager Philippe Clement was already missing Ryan Jack, Tom Lawrence and Nico Raskin from his midfield through injury as Rangers chase the win they need to guarantee progress.
Clement experienced other bad news this week. Ecuador midfielder Jose Cifuentes lost his appeal against the red card he received against Dundee on Saturday, which rules him out of Sunday’s Viaplay Cup final against Aberdeen through suspension.
And striker Danilo has been ruled out for several months with the knee injury he suffered in last Wednesday’s win over Hearts.
Clement said: “Todd is not here because of personal circumstances, and he wants to keep it personal, so we respect that. It’s nothing between the club and him, or me and him, it’s just family-wise.
“There’s a really big chance (he will be available for Sunday) but it’s not guaranteed.
“I hoped Ryan would be back but it’s not the case. Danilo will be out for several months, but I don’t want to pinpoint on an exact number of months for now until is all clear.
“I was surprised with the Cifuentes decision. None of the Dundee players reacted at the time. They just continued to attack as it was a duel with a contact. It is disappointing to lose the player for two games. But I don’t have any power in that so we will focus on the guys who are available.”
Clement is also without midfielder Kieran Dowell and defenders Leon Balogun and Ridvan Yilmaz, who are not in the club’s European squad.
“It’s quite a list of players injured and not on the European list. But it’s about the guys who are here,” he said. “They are here with ambition and to prove themselves as a team.
Rangers will go through to the knockout stages regardless of the result in Seville if Sparta Prague fail to beat Aris Limassol in Cyprus. But victory for the Czechs would leave Rangers needing to beat Betis to finish in the top two, a result which would seal top spot in Group C.
The Ibrox club are assured of European football beyond Christmas with third place sealing entry to the Conference League knockout stages.
Betis are unbeaten at home in LaLiga this season and have won both of their Group C games on home territory.
Clement said: “We have a lot of respect for them but we come here with ambition. Rangers have nothing to lose. We are in Europe next year but we want to make the next step. This may be the biggest challenge until now and we go all out for it.
“Real Betis is a different style than what we have faced. Real Madrid didn’t win here which shows how big a test it is but I feel something special in the group. I can see a really good dynamic growing in the dressing room. Everyone stays confident even after going behind.
“I see several players becoming better and better, we need to continue that story against a really good opponent.”
Meanwhile, Alex Rae has been confirmed as first-team coach on an ongoing basis after returning to Ibrox when Steven Davis took caretaker charge and staying on under Clement and assistant Stephan van der Heyden.
The former Gers midfielder told the club’s official website: “Everyone knows how much this club means to me and I am determined to help the gaffer and Stephan bring silverware back to Rangers.
“We are still in four competitions and we have a lot to look forward to this season.”