Chelsea have signed goalkeeper Djordje Petrovic from New England Revolution for £12.5m plus £1.5m in add-ons.
The 23-year-old Serbia international will compete with Robert Sanchez for the number-one spot at Stamford Bridge.
It comes after Kepa Arrizabalaga left the club to join Real Madrid on loan while Edouard Mendy signed for Al-Ahli.
Petrovic said: “It’s a big step and it’s always been a dream of mine to sign for one of the biggest clubs in the world.”
He added: “Today I have achieved that goal and I’m so happy.”
He has agreed a seven-year contract at Stamford Bridge with an option of a further year.
Petrovic played 43 times in MLS for New England and has two caps for Serbia.
Chelsea goalkeeper Marcus Bettinelli is currently out injured, while 20-year-old Lucas Bergstrom has been on Mauricio Pochettino’s bench for the first three games of the Premier League season.
The club have spent about £323m on eight players in this transfer window, more than any other side in Europe, and have broken the record for the highest summer spend by any club in the world – eclipsing Real Madrid’s £292m in 2019.
They have spent more than £850m in the market since owner Todd Boehly took over last summer.