Arsenal midfielder Francis Coquelin is expected to miss the coming games against Cologne and Chelsea after suffering a hamstring injury during the Gunners' 3-0 victory over Bournemouth on Saturday (9 September).
The French midfielder came on to replace Aaron Ramsey in the 67th minute of the game but was forced off less than 15 minutes later after picking up an injury.
Coquelin is expected to undergo a scan to address the issue but Wenger confirmed after the game that the Frenchman is likely to be unavailable for the Thursday's Europa League opener against Cologne and the Sunday's trip to Stamford Bridge.
"Coquelin has a hamstring [problem]. I don't know how bad it is but he's certainly out for next week's game," Wenger confirmed in the press conference following the win over Bournemouth.
Wenger, however, provided better news regarding Jack Wilshere after revealing that the England international is closing in on a return to action.
Wilshere is yet to play a game for Arsenal this season after he suffered a hairline fracture to his leg while on loan at Bournemouth.
But asked whether the midfielder could be back for the Thursday's encounter against Cologne, Wenger said: "I don't know yet. He's not far from that."
"I told you in the [pre-match] press conference that he's getting stronger and stronger. The fact that Francis is now out gives him a chance as well."
Danny Welbeck has been another Arsenal player hit by injuries in recent years but the former Manchester United forward enjoyed an impressive performance against Bournemouth after starting ahead of Alexis Sanchez.
The England international scored a brace and assisted Alexandre Lacazette for the other goal of the game to help the Gunners bounce back from the recent defeats to Stoke City and Liverpool.
"He gets stronger and stronger. Let's not forget that he was out for a long time. He gets stronger and stronger. He's a team player, Danny Welbeck, and that's why coaches love him," Wenger said when asked about Welbeck.
"He's a guy who has a huge physical potential. People are not convinced that he is a great finisher, but these kinds of goals will help him become more relaxed in front of goal. I liked his second goal today because it was the clean finish of a goalscorer."
Wenger then admitted that he now faces a selection dilemma to form his attack ahead of his side's double header next week.
"Yes but I have a selection problem before every game," Wenger said. "I always have to leave top-class players out, especially offensively. We have many top-class strikers."