Everton defender Joleon Lescott has told the club he wants to leave but is yet to hand in an official transfer request, BBC Radio 5 live understands.
Lescott is wanted by big-spending Manchester City, who have twice failed in their bid to sign the 26-year-old.
City have offered £15m and £18m for the England player but Everton are desperate to keep him.
Everton's stance may be weakening after it was revealed they are in talks with Arsenal centre-back Philippe Senderos.
A fee of about £6m is thought to have been discussed for the Switzerland international but an Everton club source has claimed the centre-back is not being signed as a direct replacement for Lescott.
Everton manager David Moyes has always said that no player would leave the club without his approval.
City have already signed Gareth Barry, Roque Santa Cruz, Carlos Tevez, Emmanuel Adebayor and Kolo Toure in a summer spree that has resulted in them spending about £80m.
They also recently failed with a bid to sign Chelsea centre-back John Terry.
Lescott joined Everton for £5m from Wolves in 2006 and has been capped seven times by England.