Chelsea midfielder Ruben Loftus-Cheek has ruptured his Achilles tendon and has undergone surgery on Thursday night.
Loftus-Cheek is ruled out for Chelsea's Europa League final against Arsenal in Baku on May 29, after injuring his ankle during a post-season friendly against MLS side New England Revolution.
The midfielder confirmed on Friday his surgery took place successfully and vowed to come back stronger in a message to Chelsea fans.
"Difficult to describe how I'm feeling right now. More confusion than sadness," he posted on Twitter.
"My surgery went very well yesterday evening so I'm off to a good start! I'll be watching and supporting from the sidelines for a little while so I wish the boys all the luck in the Europa League final and of course the Nations League finals.
"Coming back strong from an injury is something I've had to do all my life and I'll do it again."
England manager Gareth Southgate was forced to drop Loftus-Cheek from his preliminary 27-man squad for the Nations League finals in Portugal next month.
Southgate said the timing of the injury is "very unfortunate" because Loftus-Cheek - and his Chelsea team-mate Callum Hudson-Odoi, who suffered the same injury in April - would "definitely" have been included in his squad.
The 23-year-old came on as a half-time substitute in Wednesday's friendly in Boston, but had to be replaced after 69 minutes after he appeared to twist his foot awkwardly on the uneven surface at the Gillette Stadium.
Loftus-Cheek was then seen leaving the ground on crutches and with a protective boot on his left foot.
Hudson-Odoi suffered the injury in Chelsea's 2-2 draw with Burnley at Stamford Bridge in April.