Portsmouth chief executive Mark Catlin says only an "astronomical offer" would lead to centre-back Matt Clarke moving away from the club.
The 21-year-old has been linked with a number of Championship clubs after his first full season in League One.
The former Ipswich trainee was named Portsmouth's player of the season after 46 appearances in all competitions.
"Kenny Jackett (Portsmouth manager) wants to build a team around Matt Clarke," Catlin told BBC Radio Solent.
Clarke signed an extended contract at Portsmouth in February, keeping him at Fratton Park until 2020.
"We're not under pressure to sell, it's very much a case of keeping hold of our prize assets, unless of course there's an offer the player and the club can't turn down," Catlin said.
"It would have to some sort of astronomical offer that I just can't imagine coming. You can never say never of course, but we're desperate to keep hold of our best players."