Serbia defender Neven Subotic is a top target for Arsenal boss Arsene Wenger.
Even with the arrival of Laurent Koscielny from Lorient this week, Wenger is on the lookout for another centre-half.
The London Evening Standard says William Gallas has left the club and with Sol Campbell stalling over a new one-year deal and Mikael Silvestre surplus to requirements, Koscielny will be thrown straight into action.
Manager Wenger remains on the lookout for another centre-back even if Campbell commits his future to the club, with Johan Djourou the only other cover.
Wenger is keen on Subotic, of Borussia Dortmund, but he could cost in excess of £25m.
Other targets include Bolton's Gary Cahill, Everton's Phil Jagielka and Stuttgart defender Serdar Tasci.
