The Sunday Mirror reports that Di Matteo is keen to keep the highly-rated winger at Stamford Bridge.
Di Matteo believes the 22-year-old, who was called up to the Team GB Olympic squad, will become a ‘very good player’.
Bertrand made his European debut for Chelsea in the Champions League final victory over Bayern Munich.
“Ryan is a very talented player, who will get his opportunities to play and develop and will become a very good player,” said Di Matteo.
