Cameron Carter-Vickers will not make his comeback against Atalanta despite training ahead of the Champions League clash.
The centre-back trained at Celtic Park on Tuesday morning, but did not make the journey to Bergamo in Italy.
Manager Brendan Rodgers said: “He hasn’t travelled. Greg Taylor hasn’t travelled as well. Greg should join the group on Friday. Cam, we will see when we get back.”
The United States international’s previous appearance was in the 5-1 opening Champions League win over Slovan Bratislava. He did not finish the game after a lingering toe injury took its toll.
Celtic have only kept one clean sheet in five matches during his absence and lost 7-1 against Borussia Dortmund in their second Champions League league phase game.
Left-back Taylor has been sidelined since the Dortmund defeat with a calf problem.
Meanwhile Rodgers feels Celtic can be more compact in their latest Champions League encounter but he insisted he would never change his approach.
Celtic had contrasting results in their opening two games with a 5-1 win over Slovan Bratislava followed by a 7-1 thrashing by Borussia Dortmund.
Rodgers hopes they can learn lessons from their German trip and be tighter in certain moments, but his commitment to front-foot football remains firm.
“Listen, I started coaching many, many years ago, over 25 years ago, and from the very beginning my coaching has always been aggressive. And until the day I finish it will be aggressive, and that’s how it will be.
“But I’m also respectful that where you play against teams at a certain level, certain opponents, you have to really look at their strengths.
“But don’t say I don’t do that in every game, because I do, no matter what team we are playing, whether it’s in Scotland or in the Champions League.
“It’s the level at which you can get punished. You have to have the balance in your game, you have to be really strong defensively.
“There’s going to be moments when you can press the game high, there’s going to be moments when you’re lower on the pitch. The key learning for us has to be that when you are in those moments, you cannot go on your own.
“The occasion and the emotion, when you’ve got a very, very inexperienced squad players playing at this level, sometimes you can make little decisions to jump out of your slot when you’re defending, when really you should stay, because at this level you’ll get picked off. So that’s the key for us.
“But we always have to carry that threat. We have to attack with that intention, to play through that pressure, and know that when you can do that against Atalanta, there’s space for you. But it’s always about striking the balance.”
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