Theo Walcott pulled up late in the game and will undergo a scan on a knee injury to establish the full extent of the problem. Gunners manager Arsene Wenger admitted his concern about the England winger's availability for his side's second group game following the 1-1 draw at Borussia Dortmund.
Wenger is keen his side claims maximum points from the three home fixtures against Olympiakos, Dortmund and Marseille to help them reach the 11-point target the manager has set to ensure qualification to the knock-out stages.
But they may well have to face the Greek side at the Emirates Stadium without Walcott.
"I thought it was a classic hamstring, but it is not," Wenger said. "He felt a sharp pain in his knee."
Arsenal secured their second Premier League win of the campaign thanks to two goals from Robin van Persie and a third from Alex Song.
Van Persie skippered the side and Wenger praised the Holland forward's growing maturity in leading the side to a win that eased the pressure on the manager after the disappointing start.
"I think he is one of these guys who develops with responsibilities," Wenger said.
"He really grows well into the role. I have observed him and he does well there."
Wenger's position has come under scrutiny for the way he has overseen the rebuilding of the squad following the summer departure of Cesc Fabregas and Samir Nasri.
But quizzed about his future, Wenger restated his commitment to the Emirates Stadium club, telling reporters: "You were consistent in wanting to get me out and I was consistent in wanting to stay in and show my commitment to this club so we have always been consistent."
Wenger is convinced his side showed signs of finally hitting form after a disrupted start to the season.
"I felt in the first half we were a bit impatient, we didn't move the ball quickly enough," he said.
"Our midfielders came a bit deep and that exposed up to counter attacking.
"In the second half our midfield played high up and after we scored the first it was a case of when we would score the second.
"It was a good win for us because we cannot drop points anymore."
Arsenal were helped by the second half dismissal of Bolton defender David Wheater for a foul on Walcott as they fell to a fifth successive defeat.
Wanderers manager Owen Coyle was more concerned about his side's chances of ending their slump when they face Chelsea next weekend.
"Sometimes when you are not having the best of luck then things appear to conspire against you but we can't feel sorry for ourselves have to work hard and do something about that," Coyle said.
"We have played four of the top six, or who I think will finish in the top six. We have Chelsea next week. That will be five. So it's a tough set of fixtures.
"If we had come out of that series of fixtures with six points I would have been delighted so we are three points off that at the moment but we know we have good players.
"We are certainly have a good team and can win these matches. That’s what we have to do."