Arsenal captain Cesc Fabregas expects to be back in action in two weeks, according to his Twitter account.
The Spain midfielder suffered the injury as he scored in bizarre circumstances at Sunderland on Saturday, the ball being kicked at him by Black Cats defender Anton Ferdinand and looping into the net from 40 yards.
But he told his official Twitter account, cesc4official: "Good news on my injury.
"I have some fluid but nothing bad in the muscle. I hope I can be playing in two weeks."
The playmaker joins a lengthy list of star names currently on the sidelines at the Emirates Stadium, featuring Theo Walcott, Robin van Persie and Nicklas Bendtner.
Fabregas is likely to miss Saturday's home Barclays Premier League encounter with West Brom and the Champions League trip to Partizan Belgrade three days later, but could be back in contention for the trip to Chelsea on Sunday, October 3.