Kieran McKenna insists Mason Greenwood and Brandon Williams need to keep grounded after outstanding breakthrough seasons with Manchester United.
Greenwood, 18, made his United debut in March of last year but has already scored 12 goals in his first full season and was being touted for a senior England squad call-up.
Full-back Williams, 19, has been one of the unlikely success stories at United, making his debut in September and starting 19 matches - three more than Greenwood.
McKenna coached Greenwood and Williams when he was the United Under-18 coach before Jose Mourinho promoted the Northern Irishman to his first-team staff.