The Frenchman played 66 minutes of Celtic’s 3-0 win over Armenians Alashkert last week, netting twice, before being substituted following a hamstring injury.
The injury is not long-term but the striker will likely miss both legs with Norwegian champions Rosenborg at Celtic Park and possibly the first-leg clash with AEK Athens if Celtic progress.
Dembele has suffered muscle problems throughout his Celtic career, missing both legs of last year’s Rosenborg tie with a hamstring injury.
Celtic boss Brendan Rodgers told the club’s website: “Moussa will be out for a few weeks. Thankfully it’s not a longer-term hamstring. Sometimes these things can be six to eight weeks but it’s not that - it’s two to three weeks maximum. It was unfortunate for him as he’s looked very fit in pre-season.
“We had a scare with Odsonne as well and he only just rejoined training on Monday. After the game, his knee had swollen up. He hadn’t trained for a few days but he looked fine on Monday in training.”
It will leave Celtic with Edouard as the only striker option for the first-leg with Leigh Griffiths returning to training later in the week. Both Scott Sinclair and Ryan Christie were brought on to play in a central attacking role against Alashkert.
Jonny Hayes will also make a return to training this week.