The Premier League side have reportedly not made a concrete offer for the Dane however.
Fenerbahce's Simon Kjaer
ESPN reports that the Turkish club are yet to receive a bid for the 27-year-old, who they have valued at around £13m, but the Gunners appear to have joined the race by registering their interest.
Arsenal manager Arsene Wenger
It is hardly surprising that Wenger wants to add another defender before the window shuts.
ESPN adds that both Per Mertesacker and Gabriel Paulista are both sidelined with injury while Laurent Koscielny missed their opening day defeat to Liverpool after being given extra time off after helping France reach the final of this summer's European Championships.
With those three out, their vulnerability and lack of depth at the back was made obvious against the Reds as they conceded four goals in one game at the Emirates for the first time in over seven years.
Shkodran Mustafi is reportedly in talks with Arsenal
Kjaer is not the only centre-back on Wenger's radar however. ESPN claims that talks are taking place over Valencia's Shkodran Mustafi while Jose Fonte and Omer Toprak are also catching their eye.
Although Kjaer is yet to play in the Premier League, he has experience in several top divisions across Europe and has largely risen to the challenge at each club he has joined, so Wenger may be weighing up whether he should be capable of adapting to the English game before he potentially makes a bid.