Chelsea Land Alejandro Garnacho in £40m Transfer from Manchester United OR Garnacho Seals £40m Move to Chelsea After Falling Out of Favor at Man United OR Chelsea Secure Garnacho in Blockbuster £40m Deal; Winger Departs Man United

Chelsea have confirmed the signing of Alejandro Garnacho from Manchester United.

Garnacho arrives for a fixed fee of £40 million ($54m), sources have told ESPN, with the 21-year-old having fallen out of favour under Ruben Amorim.

Before the move was announced by either club, Garnacho was in the stands for Chelsea's home game against Fulham on Saturday, which the west London side won 2-0.

Later that day, Chelsea confirmed Garnacho had signed a deal at Stamford Bridge until 2032.

"It's an incredible moment for my family and I to join this great club," Garnacho said. "I can't wait to get started. I watched the Club World Cup and to join the world champions is special -- we're the best team in the world! It's amazing to be here and I'm very happy."

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Garnacho, who was critical of Amorim after being left on the bench for United's Europa League final against Tottenham in May, had been training away from the main group at Carrington while his future was being resolved.

The Argentina international has scored 16 goals in 93 Premier League appearances and is set to become another attacking option for Enzo Maresca at Stamford Bridge.

Information from ESPN's Rob Dawson and James Olley was used in this report.