Chelsea target John Stones would improve as a player if he were to play under Jose Mourinho, according to his former teammate and mentor Bobby Hassell.
Earlier this month the Premier League champions had a £20m offer for the England international rejected by Everton.
Hassell, who helped nurture Stones at Barnsley before the youngster joined Everton in January 2013, believes that the 21-year-old would fit in well at Stamford Bridge.
"I could see him going to play for Mourinho and getting even better," Hassell told PA. "Natural defending is what Mourinho is a master at and John's got everything else.
"He's that good on the ball, he's quick and so comfortable in possession. When he was 15 I said to people at Barnsley he would go on to play in the Premier League and for England and they laughed.
"He's a good kid and a level-headed lad. He'll deal with the pressure that will come his way, unlike a lot of other lads."
Hassell is the latest person to talk up Stones's ability, with Everton chairman Bill Kenwright and Chelsea centre-back Gary Cahill also lauding the defender.