Arsene Wenger is hopeful of doing a deal for Valencia defender Shkodran Mustafi after admitting that "negotiations are ongoing".
The Germany international has been on Wenger's wishlist throughout the off-season transfer window, and with a number of players injured for the Gunners, it is a deal the Arsenal boss is desperate to seal.
Wenger revealed, though, that Mustafi is just one of a number of players he is looking at, in order to provide cover in defensive areas.
The French boss is without Per Mertesacker and Gabriel Paulista, but was able to call on Laurent Koscielny to play alongside young centre-back Rob Holding in the 0-0 draw with Leicester at the weekend.
But, with Callum Chambers as the club's only other fit centre-back, Wenger knows a deal for Mustafi is crucial to his side's chances of competing for top honours this term.
Wenger told French TV station SFR Sport: "Mustafi? We hope it will be done. He is one of a number of players we are looking at.
"We are struggling to find the players we need, but we must be responsible.
"Mustafi is one of a number of players we are looking at, but, yes, negotiations are ongoing."
Jonny Evans, Simon Kjaer and Omer Toprak are three other player Wenger could turn to if the Mustafi deal is unsuccessful, but with Valencia needing to sell, due to Financial Fair Play regulations, the club may just get their man.
Valencia sporting director Jesus Garcia Pitarch explained: "We're above the FFP guidelines, that's the reality, and as of today, the four players we've signed cannot be registered.
"This means we need to reduce the cost in a significant manner to register the players and sign a centre-back, which is a priority in case one of the ones at our club leaves."