Arsenal midfielder Francis Coquelin faces three weeks on the sidelines with a knee injury, manager Arsene Wenger has said.
Coquelin was forced off after 32 minutes of the Gunners' 3-0 Premier League victory over Chelsea on Saturday after coming off worse in a challenge with N'Golo Kante.
There were concerns the 25-year-old could face a longer spell out of action, but Wenger expects him to be available mid-way through October after scans determined that the problem was not severe.
"Francis Coquelin is out for the game - it should be a short-term injury," Wenger said ahead of Arsenal's Champions League clash with Basel. "The scan was quite positive."
When pressed for a time frame, Wenger replied: "It could be three weeks".
The Gunners boss added that striker Olivier Giroud - banned for the Basel match - is a doubt for Sunday's game with Burnley due to a toe injury.
Looking ahead to Wednesday's game at the Emirates Stadium, Wenger hopes his side can produce the same intensity with which they dismantled Chelsea when they take on a side who have won all of their nine league games this season.
"They're used to the Champions League, they have huge experience and I don't expect them to be intimidated," he said. "They have nothing to lose and they are dangerous."
Of his own team's latest efforts, he said: "The relentless team energy, and that they kept going [impressed me the most against Chelsea]. I think it's a sign of maturity. We had style and steel and combined both.
"But it's a new challenge every time - the humility is to accept that you have to start from scratch again. We have to find the resources to win again."
