Kolo Toure will miss Celtic's friendly with Spanish giants Barcelona in Dublin on Saturday but could play for his new club in next week's key Champions League tie against Astana.
The 35-year-old Ivory Coast centre-back, formerly with Arsenal, Manchester City and Liverpool has yet to feature for his new side since joining the Glasgow club last week.
Scottish champions Celtic have a defensive injury crisis, with Erik Sviatchenko, Jose Simunovic, Dedryck Boyata and Kristoffer Ajer all sidelined.
And with their Champions League third qualifying round tie against Astana poised at 1-1 ahead of Wednesday's second leg at Parkhead, it is easy to see why they would want to avoid an injury to Toure in a friendly match, no matter how prestigious the opposition.
Celtic coach John Kennedy, speaking at Glasgow Airport ahead of the team's departure to Ireland on Friday, said: "It's pretty much the same squad we had in Astana.
"Kolo is still working fitness-wise so he also stays back to do some extra work. It's still a bit early for him to play in tomorrow's game. We will look at that again and assess that on Monday.
"It depends how he comes through the next few days (whether he can play against Astana). If he shows his fitness levels are good enough he is an option.
"Erik won't travel over. We'll see how he is in the next couple of days. It's better for him to stay at home and get some treatment.
"We just have to deal with tomorrow (Saturday) and see how everybody comes through.
"We've got Kolo in the back of our minds and that is why he has stayed behind to work. Come Sunday we can assess everybody and see where we're at."
Kennedy added: "We are short defensively, though. There's no question about that. We just have to make sure whatever we put on the pitch against Astana is strong enough to win the game."
Despite their injury problems, Kennedy said Celtic were looking forward to Saturday's match against Barcelona.
"We're playing a top team so it's good to test yourself against that," he said. "For us it is good preparation for Wednesday.
"Testing yourself against the best gives you a great mark of where you are at.
"Barca will probably make us run a little bit so that will help us top up our fitness levels as well."
Meanwhile, Kennedy confirmed that Celtic manager Brendan Rodgers was interested in signing Aston Villa winger Scott Sinclair, who previously worked with the Hoops boss at Swansea.
"There are a number of targets we're looking at but we need to make sure they are the right ones," he said.
"He (Sinclair) is one that has been mentioned but he's still an Aston Villa player. We want to bring quality in and that is certainly the calibre of player we're looking at."
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