Ruben Amorim has described Kobbie Mainoo as not the 'finished product' as the 19-year-old's future at Manchester United remains uncertain.
Amorim is a big fan of the England midfielder's potential but indicated there is a danger of him being over-hyped.
Mainoo, one of the poster boys for United's famed academy, is under contract until 2027 but talks with his representatives have reached deadlock as they look for £180,000-a-week plus bonuses.
To help with profit and sustainability rules, United are ready to let Marcus Rashford leave in the January transfer window and are also open to selling fellow homegrown players Alejandro Garnacho and Mainoo, who is valued at £65million.