Galatasaray are desperate to sell Mbaye Diagne before signing Monaco striker Radamel Falcao a source close to the Lions revealed to Turkish-Football.
The Lions must raise an additional €5m as part of their Financial Fair Play arrangement.
Diagne scored 32-goals in all competitions last term playing an important role in Galatasaray winning the Super Lig and Turkish Cup.
The Yellow-Reds sent Sukru Hanedar who is in charge of foreign transfers to London at the start of the week to find Diagne a new club.
Aston Villa have been closely linked with Diagne but could face competition from other Premier League sides who have also expressed an interest.
Hanedar is in London hoping to cash in on Diagne in a transfer window deadline day deal.
The Galatasaray official is expected to travel to France once the window shuts to complete the transfer of Falcao.
The Lions want to find Diagne a new club before signing Falcao due to the high fees involved in the deal.
The Colombian striker has been closely linked with a move to Galatasaray for weeks but despite rumours of a deal being imminent talks have dragged on.
The Yellow-Reds are finally close to completing the transfer but still have a few final hurdles to pass.