Arsenal defender Kolo Toure is facing up to a spell on the sidelines after picking up a calf injury on Tuesday.
The centre-half sustained the knock during the Gunners' 3-1 victory over West Brom.
The Ivorian had enjoyed a productive evening at the Hawthorns until he was forced off, notching his first goal of the campaign and laying on the third for Nicklas Bendtner.
However, having struggled through to half-time, he was then replaced by Abou Diaby at the break.
Arsene Wenger admits Toure has suffered a setback, but remains unsure as to how long the 27-year-old will be out of action.
"He has a calf problem that we cannot assess at the moment because his pain is moving a little bit," Wenger told the club's official website.
"We will have to assess that on Wednesday."