Updated: Jul 20, 2020
Scotland Under-21 international Billy Gilmour injury means he will be out for a lengthy spell.
19-year-old Gilmour came on as a substitute in Chelsea's win over Watford but got injured during the game.
Chelsea manager Frank Lampard says midfielder Billy Gilmour will be out of action for about three to four months after having a successful knee operation.
The Scot, who joined the Stamford Bridge club from Rangers in 2017, has been training permanently with the Blues' first-team this season and has been really impressive, making 11 appearances this season.
"I'm very disappointed, as we all are here," said Lampard as BBC Sport quoted.
"He's a tough boy, it hit him hard especially as a young boy who has just made a breakthrough."
One of Gilmour's best games so far was when he helped the Blues beat Liverpool in the FA Cup fifth round in March.
"I told him he should be very pleased with what he's done and the impact he's had this season anyway," added Lampard.
"His attitude will get him back as quickly as he can."