Neil Lennon has revealed Vakoun Bayo may require knee surgery that could keep him out for six weeks as his forward line injury headache worsens.
The Ivorian missed the 2-0 win over St Mirren after undergoing a scan and his absence leaves the Hoops with just one fit striker in Odsonne Edouard.
Skipper Scott Brown was also withdrawn as a precaution after tweaking his thigh ahead of Saturday's Betfred Cup semi-final against Hibs.
But Celtic had already wrapped up the points by the time their skipper departed as second half goals from Mohamed Elyounoussi and James Forrest retained their place at the Premiership summit.
Lennon urged his players to be more assertive at half-time and they responded to win their third league game on the bounce.
After providing the injury update, Lennon told BBC Scotland: "I needed a bit more oomph and we certainly got that second-half.
"We could've won the game by a lot more. I wasn't unhappy with the first half performance but we played into St Mirren's hands a little bit by just being hesitant with our passing and forcing things.
"The second-half was tremendous - no panic. The two goals were great and it could've been three or four. It was another good night's work.
"We know the situation, if we drop points we're going to be heavily criticised but if we win people see it as routine.
"We don't see it that way, there's a big effort from the players at the minute.
"We changed it a little bit and gave Greg Taylor his debut, he can be delighted with that.
"So I'm very happy with the volume of chances we're creating and the fact we came out after half-time and did the same as we did against Ross County, turning up the heat.
"It all bodes well for the rest of the season."
Celtic remain level on points with Rangers but still top the league via a superior goal difference, despite their rivals thumping Ross County 4-0.
