Diego Poyet is set to leave Charlton Athletic after the midfielder informed the Championship club he wants to explore options elsewhere.
The 19-year-old had been offered a new contract by the Addicks but will not report back for pre-season training.
Diego, the son of Sunderland manager Gus, came through Charlton's academy and made 23 appearances last season after making his debut in January.
Charlton will receive compensation when the teenager joins another club.
The south-east London club had been in negotiations with Poyet's representatives over a new deal and say they had offered the midfielder "substantially improved terms" in order to retain his services.
Poyet was voted Charlton's Player of the Year by supporters after breaking into the first-team set-up and helping the Addicks secure their Championship status.
Earlier this week new Charlton head coach Bob Peeters told BBC London 94.9 he hoped Poyet would sign a new deal, describing the former England Under-17 international as "one of the biggest talents in the Championship last season".
"We are extremely disappointed that Diego has turned down our offer for him to stay with us," Charlton director Katrien Meire told the club website.
"We did all we could to persuade him to remain with the club.
"Along with our fans, I enjoyed watching his progression last season and hoped we would continue to enjoy his development at The Valley."