Chelsea has set a Friday deadline at 17:00 BST for clubs to submit offers of at least £120m for midfielder Enzo Fernandez.
The Argentina international has faced uncertainty over his future since March, when he indicated a potential move to Real Madrid.
Real Madrid have since ruled out signing Fernandez, leaving Manchester City as the only known potential suitor.
City have yet to indicate whether they would meet Chelsea’s valuation and are also targeting Lille midfielder Ayoub Bouaddi.
Chelsea expect to stand firm on their £120m asking price despite having paid £107m to sign Fernandez from Benfica in 2023.
The deadline is designed to resolve the uncertainty before the new season begins, with the club contending they have allowed approximately 60 days to complete a deal at what they consider a fair price.
New manager Xabi Alonso has spoken to Fernandez about his future but declined to disclose details.
Chelsea have made clear they are willing to fully reintegrate Fernandez into the squad and regard him as a key player if no suitable offer arrives.
Fernandez scored 15 goals and provided seven assists in 54 appearances last season and subsequently helped Argentina reach the World Cup final, where they lost to Spain after he was sent off.
He returned to Chelsea training this week under Alonso, with his future set to be decided by Friday’s deadline.