Neil Lennon admits Celtic are facing an injury sweat after Kris Ajer hobbled off during the emphatic win win over AIK.
The Premiership champions were on fire as they swept aside the Swedes 4-1 on the night and 6-1 on aggregate to book their place in the Europa League group stage.
But the victory came at a cost with Odsonne Edouard also exiting early.
The Celtic boss is facing a selection headache ahead of Sunday's clash with Rangers at Ibrox with Ajer extremely doubtful.
Fellow right-back's Hatem Abd Elhamed is working his way back from injury and new signing Moritz Bauer isn't up to speed.
Goals from James Forrest, Mikey Johnston, Chris Jullien and Lewis Morgan made it an easy night's work the Hoops.
Ajer's game was over in the 13th minute as he appeared disconsolate as he trudged off and Edouard was also forced to call time on his evening. He was replaced by Vakoun Bayo.
Lennon concedes Ajer is facing an uphill battle to shake off his knock but there is more encouraging news on Edouard, who on Thursday was called up to the France U21 squad for the first time.
The manager said: "It's a groin strain for Kris so he's going to be very doubtful for Sunday.
"Odsonne should be fine as he came off with bit of cramp."
Lennon was blown away by his side's display after they earned a big win against the over-matched Swedes.
The hammering thrilled the Irishman as he can now start focusing on European football until Christmas.
He added: "It was an awesome peformance.
"I thought the front four were marvellous. We defended well and we looked assured.
"Every time we pushed forward we looked really dangerous.
"We have a big game on Sunday but the lads have bounced back perfectly after the Cluj result."
