Arsenal have made an enquiry about Fenerbahce defender Simon Kjaer, a source close to the club told ESPN FC.
Fenerbahce want to keep hold of Kjaer over the summer and have yet to receive a formal offer, the source said.
Arsenal would have to make the Turkish club an offer that exceeds their €15 million valuation.
Gunners manager Arsene Wenger is facing a defensive crisis with Per Mertesacker and Gabriel Paulista both out injured.
Meanwhile, Laurent Koscielny was ruled out of Sunday's 4-3 defeat to Liverpool in their first Premier League game of the season due to lacking match fitness following his participation with France at Euro 2016.
Wenger wants to bring in defensive reinforcements before the end of the transfer window and the club are in talks over Valencia's Shkodran Mustafi, while sources have told ESPN FC that the Gunners are also interested in Manchester United target Jose Fonte.
Kjaer has been identified as an alternative for the Germany international defender as reportedly has Bayer Leverkusen centre-back Omer Toprak.
Denmark international Kjaer still has another three years remaining on his contract and has settled into life in Istanbul since joining the club from Lille last summer.
Fenerbahce have already turned down offers for Kjaer during the transfer window with Napoli as well as Chelsea linked in the past months.
Kjaer made a total of 45 appearances for Fenerbahce in all competitions last season and is expected to start against Grasshoppers in the Europa League qualifierfinal first-leg tie on Thursday.