Maurizio Sarri has warned Callum Hudson-Odoi that he must improve defensively in order to become a first-team regular at Chelsea.
Hudson-Odoi had an impressive pre-season for Chelsea but the 18-year-old forward has only made one appearance in the Premier League since the start of the campaign.
The England Under-19 international replaced the injured Pedro in the 43rd minute at Watford before being replaced with five minutes remaining as Sarri looked to defend Chelseas 2-1 lead.
Recent reports suggest Bayern Munich are attempting to lure Hudson-Odoi away from Stamford Bridge and even had a £20million bid rejected for the youngster.
Asked about Hudson-Odoi ahead of Chelseas clash with Southampton, Sarri replied: Hes a very good player, the potential is for becoming a great player, and now he has to improve
He has to improve, I think, in movement without the ball.
As a winger, he has to improve in the defensive phase, but he has the potential to become a very important player, not only for English football I think but for European football.
Sarri insists its not easy to give academy prospects like Hudson-Odoi regular game-time at the top level.
Asked if youngster such as Hudson-Odoi must be more patient for their chances, the Italian responded: Also the fans sometimes, also the club sometimes, and so I am in the middle. I have to win.
Its not easy at this level to take the young players from the academy and hes ready to play, not only here, everywhere in Europe.