Arsenal defender Per Mertesacker was forced off against Hull City on Tuesday night following a clash of heads with Nick Powell as the Gunners' injury problems continue to mount.
The Germany international jumped for a header with the Manchester United loanee and, despite attempting to continue, was subsequently withdrawn, with Nacho Monreal introduced as his replacement.
Arsenal currently has six players on the treatment table, with Petr Cech, Santi Cazorla, Laurent Koscielny, Alex Oxlade-Chamberlain, Tomas Rosicky and Jack Wilshere all unavailable for selection at present.
Wenger now faces a severe defensive headache ahead of this weekend's clash with West Brom, with his first-choice central defensive partnership likely to be absent.