Former Arsenal and England centre-back Martin Keown has advised John Stones to reject a move away from Everton.
The 21-year-old is being heavily linked with Chelsea, Manchester City and Manchester United, with reports suggesting that Chelsea have had two bids rejected.
Keown insists that Stones has the potential to become a leading defender, but he is not yet experienced enough at the highest level.
He told 888sport: "I think it's very early days. He's only really had one season in the Premier League and he hasn't yet become a man. I feel he needs to stay at Everton because there are things he needs to work on in his game. I'd like to see him more commanding from crosses and set pieces."
Stones played 28 times for the Toffees last season.