Mikel Arteta, Arsenal manager, has left Emi Martinez for their trip to Fulham on Saturday.
Villa have been favourites to land Martínez who will cost around £20m.
The Midlands club bid £15m this week, but Brighton have exceeded their offer and Martínez will not face Fulham with transfer talks ongoing.
Martínez was a revelation when he deputised for the injured Leno at the back end of last season, helping Arsenal to victory in the FA Cup final, and wants No 1 status after a decade as a deputy or on loan. But Mikel Arteta has been unwilling to guarantee that to either of his keepers and Martínez, 28 and desperate for regular football, now looks certain to leave.