Mikael Lustig could be out of action for at least a fortnight.
The defender started against Brechin City in the Scottish Cup but was substituted at half-time against Partick Thistle then left out of the team that beat Hibs.
Brendan Rodgers can switch to a back three with Dedryck Boyata or Kris Ajer on the right or look to play Anthony Ralston or Cristian Gamboa at right-back.
Ralston hasn’t played since September due to a knee injury while Gamboa fell out of favour after electing to play for Costa Rica in the Gold Cup rather than be available for Celtic’s Champions League qualifiers.
“Mika has been struggling for four or five weeks with his Achilles,” Rodgers revealed to The Sun. “You could see it was affecting performances, so him and I spoke and it’s best to get it settled.
“Hopefully he’ll be back training within a couple of weeks as he’s been a real stalwart for me since I’ve been here with his availability for games, the number of games he has played as well as his performances.
“I hope we’ll get that right and then take it from there. We just have to see how he responds and comes back for Zenit.”
At present Celtic are without Leigh Griffiths, Craig Gordon, Lustig, Marvin Compper, Stuart Armstrong, Tom Rogic, Mikey Johnston, Patrick Roberts and Jonny Hayes through injury.
New signing Charly Musonda is expected to make his debut tonight against Hearts.
