Brendan Rodgers believes the explosive nature of Moussa Dembele's play has led to another hamstring injury which will see him miss Celtic's Champions League second-round qualifier against Rosenborg at Parkhead tonight.
The 22-year-old French striker scored a double in last week's 3-0 home win over Armenian outfit Alashkert which helped the Scottish champions to a 6-0 aggregate victory before limping off in the second-half.
Rodgers, who also revealed that Odsonne Edouard has shrugged off a knee injury ahead of the first leg against the Norwegian side at Parkhead, said of Dembele, a player who has had a hamstring problems in the past: "Moussa will probably be out for a couple of weeks, certainly both legs of this round.
"It is a minor strain. Sometimes the hamstring can be six to eight weeks but this is one that from the time it happened, we have been told two to three weeks maximum.
"It is unfortunate because he has looked very good over pre-season but he will be back fit and strong.
"Maybe he has it once or twice a year. Sometimes you get that with explosive players.
"As I say, they are into the season early. He couldn't have done any more. He came back lean and fit, it is just one of those unfortunate things. But he will be back soon.
"I feel for all the coaches up here, in terms of Champions League, Europa League and the (Betfred) cup games.
"Managers and players are expected to be in full flow within one or two weeks which is unrealistic really.
"I feel for all managers and players who are having to get teams out to win games when this is the time of the season is for fitness."
Celtic have reached the Champions League in the last two years but face four instead of three qualifiers this season.
AEK Athens are waiting in the next round should the Bhoys get past Rosenborg, whom they beat 1-0 on aggregate in the penultimate Champions League qualifier last season and who will have a new face in the technical area this time.
Kare Ingebrigtsen and his assistant Erik Hoftun were sacked by the Norwegian side last week after beating Valur of Iceland
The decision led to the Rosenborg players issuing a statement in which they "vehemently disagreed" with the move, but the upshot is that interim boss Rini Coolen is now in charge.
"Obviously the manager previously had great success and it sound like he built up a real bond with the players," said Rodgers.
"For them to qualify and for him to lose his job was obviously a surprise and the support of the players and the supporters showed they maybe weren't so happy with the decision.
"However, the club has made the decision and the players and the new coach has to move on.
"It can work one or two ways. It can either galvanise the team or it can have a negative effect.
"But our concentration is very much on ourselves to do our own job and we will look to do that over the two legs."