Arsenal boss Arsene Wenger is eyeing Borussia Dortmund defender Neven Subotic.
The Daily Mail says Wenger could step up his pursuit of Subotic amid fears William Gallas could leave Arsenal for nothing in the summer.
Frenchman Gallas is out of contract at the end of the season and although negotiations are due to start about a new one-year deal, there has been talk the 32-year-old is keen to move abroad.
Gallas is believed to want a longer contract than the 12 months the Gunners will offer.
Wenger has been monitoring Subotic since he joined Mainz as a teenager and he has impressed at Dortmund, where he signed a new deal until 2014 earlier this year.