Arsenal striker Nicklas Bendtner will be out for approximately four weeks after injuring his groin in the North London derby win over Tottenham Hotspur on Saturday.
The 21 year old Danish international lasted just 37 minutes of the 3-0 win before he was replaced by Eduardo.
“It was a serious one and we go into a period where you need all your players,” said manager Arsene Wenger.
“It’s a shame that we lost him today and I am quite scared that he will be out for a while.
“It is a groin injury and I am scared it could be three or four weeks.”
It is now likely that Bendtner will miss the Champions League games against AZ Alkmaar and Standard Liege, as well as the Premiership clashes with Wolves, Sunderland and Chelsea, and the League Cup quarter final tie at Manchester City.
He joined Arsenal in 2005 from FC Copenhagen.