Chelsea sign Ukrainian winger Mykhailo Mudryk from Shakhtar Donetsk
Financial details of the transfer were not revealed, but British media reported Chelsea hijacked Arsenal's move for the forward and agreed to pay £88.5 million, of which £26.5 million are in add-ons.
"This is a huge club, in a fantastic league and it is a very attractive project for me at this stage of my career," Mudryk said in a statement.
"I'm so happy to sign for Chelsea," Mudryk said.
"I'm excited to meet my new team-mates and I'm looking forward to working and learning under Graham Potter and his staff."
Todd Boehly, Chelsea chairman, and Behdad Eghbali, co-controlling owner, said: "We are delighted to welcome Mykhailo to Chelsea.
"He's a hugely exciting talent who we believe will be a terrific addition to our squad both now and in the years to come. He will add further depth to our attack and we know he'll get a very warm welcome to London."
