Celtic have reportedly learned the extent of Liel Abada's injury.
The Scottish champions will be without the Israeli winger for up to a month.
The 21-year-old sustained the knock during training while away on international duty.
He travelled back to Scotland for further assessment of the quad injury.
Now, the Scottish Sun states that Abada will be out of action for around a month while he recovers.
It means Brendan Rodgers will be without the talented attacker for Champions League games against Feyenoord and Lazio.
Israeli outlet Sport5 says: "The 21-year-old seems to be angry mainly with himself because he chose to continue kicking at the end of the training even though it was a permission and not an obligation."
International boss Alon Hazan said: “He felt a pinch in his muscle.”
Rodgers has several first team players on the treatment table at the moment.
Defensive trio Cameron Carter-Vickers, Maik Nawrocki and Stephen Welsh are all out until the end of October at least.
Reo Hatate has also been ruled out since the second game of the season, although is expected to be fit after the international break.
Abada recently signed a new deal to keep him at Celtic until the summer of 2027.
Meanwhile, Reo Hatate will be like a new £10m signing for Celtic upon his return from injury.
Chris Sutton believes the midfielder will go on to rediscover his form of last season under Brendan Rodgers.
The former Hoops striker has made no secret of the fact he found it baffling that Hatate didn't start the first two games of the season for the champions.
The Japanese star would eventually pick up a calf strain after coming off the bench against Aberdeen, which has ruled him out until after the international break.
Sutton hinted the strange situation could've been transfer-related, and there was certainly no shortage of clubs interested in Hatate.
But the pundit cannot wait to see him back in the starting XI under Rodgers.
He wrote in the Daily Record: "Reo Hatate could end up looking like Celtic’s 10th new summer signing.
"If Brendan Rodgers gets him back and flying, it’ll be like adding a brand-new £10m player with the window just closed."
