Arsenal boss Arsene Wenger is trawling the free agents market.
The Daily Mail says they lack of depth in defence was apparent on Tuesday night when Arsene Wenger was left with just three senior defenders for their 2-0 defeat by Borussia Dortmund.
The club are looking for a central defender to provide cover for Per Mertesacker and Laurent Koscielny.
Clubs can still sign free agents despite the transfer window closing on September 1.
Scouts have been asked to examine short-term options Diego Lugano and Joseph Yobo, who are both available and have been discussed at the club's London Colney HQ.
