Marc Guehi joined Crystal Palace from Chelsea in 2021
Crystal Palace must keep hold of captain Marc Guehi if they are to have a successful season, says manager Oliver Glasner.
Guehi scored as Palace beat Aston Villa 3-0 on Sunday night just three days after the club got through qualifying for the Europa Conference League.
The 25-year-old, who has one year left on his contract, has been the subject of an improved bid from Liverpool of £35m, which includes a 10% sell-on clause.
The Premier League transfer window closes on Monday at 19:00 BST.
"I told the chairman we have to keep Marc if we want to play a successful season," Glasner told BBC Sport.
"We have no chance to find the right replacement in one day. We all agreed that we just sell Marc if we have the right replacement in the building.
"We wanted a replacement by 1 July. It is 31 August and we have no replacement. We have this agreement so it is clear from me. He is such a crucial player. He is one of our key players - he is our captain."
Guehi has made clear he does not intend to sign a new contract at Selhurst Park and the club are reluctant to let him leave for nothing when his deal expires next summer.
Palace rejected a £65m deal to sell Guehi to Newcastle last year.
They have already lost one of their key players who helped them to FA Cup glory last season, as England forward Eberechi Eze joined Arsenal for £60m.
Speaking on Sunday night after the match at Villa Park, Guehi did not discuss his future.
"All I know is when you score goals like that it is always down to team performance," he said. "People will try to single out the goal but that was a clear team performance tonight."