German international Per Mertesacker has passed a medical and agreed terms with Arsenal, according to Sky Sports News.
The Werder Bremen defender has been in discussions with the Gunners all day over a potential move to the Emirates Stadium.
Arsenal manager Arsene Wenger turned his attentions to the 26-year-old after being priced out of a move for Bolton Wanderers' Gary Cahill.
Wenger has also set his sights on Brazilian full-back Andre Santos.
The Fenerbache defender is expected in London tomorrow for a medical.