Centre-backs Toure and Simunovic stayed in Glasgow to work on their fitness, while Griffiths is ill.

Left-back Kieran Tierney had already been ruled out through injury.

Striker Raffael and midfielder Thorgan Hazard, who both missed Gladbach's 2-0 win in Glasgow through injury, face fitness tests.

Coach Andre Schubert said: "We didn't do an awful lot in training, but it's great to have Raffael and Hazard back.

"We'll see how they're feeling tomorrow then decide how big a role they can play in tomorrow's match."

Defenders Mamadou Doucoure and Marvin Schulz and forward Josip Drmic are back training but missed Friday's German Bundesliga game against Eintracht Frankfurt.

Midfielder Ibrahima Traore and defenders Andreas Christensen and Alvaro Dominguez also missed the 0-0 draw through injury.

It was a fourth league game in a row in which Schubert's side have failed to score.

But another win over Celtic will take them five points clear of Brendan Rodgers' side in Champions League Group C.

That would boost the Germans' chances of beating Manchester City to the runners-up spot behind leaders Barcelona.

It would also leave the Scottish champions adrift at the bottom and with only an outside chance of even salvaging third place and qualification for the Europa League.

Will Celtic change their shape at the back?

Toure has not played in Celtic's three domestic victories since being at fault for both of Gladbach's goals in Glasgow and has an abductor injury.

Until then, he and Simunovic had been rotating in central defence beside Erik Sviatchenko.

The Croat, who has returned this season after an eight-month injury absence, is struggling to play so soon after starting in Saturday's 1-0 Premiership win over Aberdeen.

Rodgers said: "You hope those players can get back as quick as they can, but it is an on-going issue with Jozo and Kolo."

Asked if the absence of Simunovic and Toure would result in Celtic changing their shape at the back, assistant Chris Davies replied: "We might do. We've got the option to.

"We've taken enough defenders. We've got a big squad and this is a period when that benefits us because we've got a few injures.

"We've got plenty of players that can play in that position that we trust who we know are good players, so there are no problems there."

Davies thought that Celtic had learned enough from their home game to devise a plan capable of winning in Germany.

Schubert, on his part, said he would take Celtic's absences - and the threat of on-form striker Moussa Dembele - into consideration when picking his own side.

"It's going to be a difficult, but we want to take control of the game and then see if we can get one, two or three goals," he said.

"Celtic are a dangerous team because they have nothing to lose. They can afford to take risks.

"They have players like Dembele, who we need to keep a close eye on."