Exeter City say they are “disappointed for football” after a tribunal ordered Chelsea to pay the League Two side up to £2.5m for Ethan Ampadu.
The potential fee would be an Exeter record, but chairman Julian Tagg said the ruling “sends the wrong message” to clubs producing home-grown players.
Wales defender Ampadu, 17, moved to Stamford Bridge last summer having come through Exeter’s youth academy.
He has made seven appearances for Chelsea so far this season.
He has also played twice for Wales, making his debut against France on 10 November and then his first start four days later against Panama.
Exeter chairman Julian Tagg told the club’s official website: “Whilst the club recognise, that the compensation fee is not a transfer fee, but instead to reward the club for its investment in the training and development of a proven outstanding player, and that the tribunal has awarded Exeter significant contingent sums, to say that we are disappointed is an understatement.
“We are disappointed for our fans, our academy, which works so hard on producing talented young players like Ethan and for our management and coaching team who bring these players into the first team and beyond as part of supporting the work of the FA in its objective to produce international players of the highest quality which we believe we have done.
“However, above all, we are disappointed for football as we feel this decision sends the wrong message in terms of financial reward for those owners, chairmen, managers and coaches up and down the country who are also working as hard as us to improve their clubs by producing talented home-grown players for both club and country.”
Ampadu became Exeter’s youngest ever player when he made his debut aged 15 years and 330 days. He went on to make 13 first team appearances.
He has also made two senior appearances for Wales, in friendlies against France and Panama.
Exeter are guaranteed to receive £1.3m based on a transfer fee plus the international and first-team appearances he has already made.
Further payments will be made when Ampadu makes a set number of appearances for Chelsea, while Exeter will also receive a 20% sell-on fee should he leave Stamford Bridge.
Exeter’s existing club record sale is the £1.8m Brentford paid for striker Ollie Watkins in 2017.