You tanked his value. He was a project of a potentially great player when you signed him and in 3 years he didn't improve one bit. For the past half season was getting benched by Dalot. He's turning 25 early next season now, and on wages that for every club outside those 14-15 megarich/megaspenders are huge wages. And you want him out. Nobody's gonna sign him outright. Best you can do, send him on loan and hope he does well and rebuilds his value. Then sell next year
To be fair we've mismanaged every single player's career at the club. But as you've alluded to - onwards and upwards.