Steven Gerrard fears Rangers' "crazy" win over Antwerp has come at a cost after seeing both James Tavernier and Kemar Roofe limp off injured in Belgium.
The Ibrox side edged the rollercoaster Bosuilstadion clash 4-3 to claim a vital first-leg lead ahead of next week's Europa League return in Glasgow.
But while Gerrard admits his team must improve if they are to reach the last 16 for the second year running, he also fears they will have to do it without skipper Tavernier and frontman Roofe.
The Light Blues boss branded pre-match reports that Tavernier had picked up an injury ahead of his side's trip to Flanders "fake news" but the discomfort on his captain's face looked real as he was forced off after a collision with Martin Hongla.
Roofe also had to be replaced just before the break but Rangers still had enough quality to twice come from behind to clinch a dramatic win thanks to Borna Bariasic's penalty double plus strikes from Joe Aribo and Ryan Kent.
Asked for an update on his stricken pair, Gerrard said: "I'm concerned for both. Right now, I'm more concerned for Kemar because he feels it's the same as a previous injury when he missed two to three weeks.
"He's got a calf problem but we'll get it looked at in a scan.
"With James, we'll have to wait and see. He's obviously gone in for the block tackle and felt some pain in the knee area. We'll get him scanned as well and go from there.
"Obviously I feel really good in terms of the result but I feel for both players because they are very important for the group."
With Gers potentially just weeks away from lifting their first Scottish title in a decade, an injury could not come at a worse time for Tavernier having endured his fair share of disappointments over his six-year Ibrox spell.
But Gerrard is not ready to rule the right-back out of the title race just yet, saying: "That's very pessimistic – I'm trying to stay optimistic. This is my captain, he has been absolutely unreal for me since I came in the door.
"We will check it out and, knowing James, he will be desperate to get back as soon as possible.
"He's had a fantastic run in terms of injuries. We have a fantastic medical department who will analyse it and tell me what's what.
"Let's just hope the scan news is more positive than negative."
Gers dominated the first half but only had Aribo's goal to show for it as he pounced on a mistake from Antwerp keeper Alireza Beiranvand.
The hosts got two helping hands from referee Georgi Kabakov as Felipe Avenatti headed home from a soft free-kick award while Lior Refaelov netted a penalty in the eighth minute of stoppage time from another generous spot-kick decision.
Rangers hit back with the first of Barisic's double only to fall behind again to Hongla's goal.
But the drama was not done there. A string of chances went begging at either end before Kent's equaliser was followed up by another Barisic penalty as Abdoulaye Seck saw red for a late handball in the box.
"I'm obviously very pleased with the outcome of the game in terms of the result," added Gerrard. "I think the boys showed amazing character to fight for the right result.
"It was a crazy match. I'm sure the neutrals enjoyed it but as a coach I'll be looking into it because we had too many issues defensively.
"The goals we've conceded are poor from our point of view. There is certainly work and a lot of improving to do.
"At this level, you get punished a lot more.
"We've put ourselves in a promising position and it's very difficult to win away from home.
"So there's a lot of me that's pleased and proud but there's still things going around in my head about needing to improve defensively."