Exeter City boss Paul Tisdale gave 15 year-old Ethan Ampadu his debut as the League Two side beat Championship club Brentford 1-0 in Tuesday's opening round of the EFL Cup.
Ampadu was only called up to the first-team because he is on school holiday.
"The biggest compliment I can give him is that he plays like a 35-year-old," Tisdale told BBC Radio Devon.
"That's not normally the English way - we like drama, we like spark. But we don't often encourage and cultivate subtle, classy players, and he's one of those."
Ampadu has attracted enquiries from Manchester United, while his father, Kwame, is a coach with Arsenal academy.