Arsenal were hoping to sign Mustafi in order to ease a long injury list of defenders. Per Mertesacker and Gabriel are both out injured, leaving Laurent Koscielny, Callum Chambers and Rob Holding as the club's only options in central defence.
However, it now looks like Wenger will have to switch his focus elsewhere, as Mustafi's current manager at Valencia claimed that he will not leave the club.
Ayestaran said: "Mustafi is not for sale and will not be leaving the club".
It therefore seems that Arsenal's only hope of signing the German is to activate the player's release clause hich stands at €50m, a price that Arsenal chiefs would likely deem too expensive.