Manchester City have received a bid of more than £20million for defender Eliaquim Mangala from Crystal Palace, Press Association Sport understands.
The London club may have turned their attention to the 26-year-old centre-back after failing to make progress in their pursuit of Liverpool's Mamadou Sakho.
Palace are now awaiting a response from City, who could be highly active on transfer deadline day.
Selling Mangala, who spent last season on loan at Valencia, could prompt the club to accelerate efforts to land Jonny Evans from West Brom.
City have failed with two previous bids for former Manchester United defender Evans, the most recent worth a reported £18million.
Evans, who is currently on international duty with Northern Ireland, has also attracted interest from Leicester and Arsenal.
City have spent more than £200million on players during the summer transfer window but are still keen to bring in a central defender.
Mangala, who has failed to impress since joining the club in a £42million deal in 2014, is surplus to requirements but has been involved in the first-team squad this term due to necessity.
City's other chief interest on deadline day could revolve around Arsenal's Alexis Sanchez.
City had a Â£50million bid for the Chile forward turned down on Tuesday.
The club have not submitted a fresh offer but it is understood negotiations remain open.
Sanchez is in the final year of his contract at the Emirates Stadium and has been linked with a move to City throughout the summer.