Chelsea have signed Aston Villa 18-year-old Carney Chukwuemeka on a six-year contract for a fee in the region of £20m.
The Nigeria-born midfielder made 12 Premier League appearances last season but only started twice and it is understood he is keen to get more top-flight game time.
“It’s been quite hectic but I couldn’t get Chelsea out of my head the last few days so I’m just happy and relieved that it’s all done,” Chukwuemeka told the club’s official website.
“I’m so excited and just can’t wait to get on the pitch, meet all the players and try to win games and trophies with Chelsea.”
Chelsea chairman Todd Boehly added: “Carney is one of the most exciting young players in Europe so we are really looking forward to seeing him in action at Stamford Bridge.
“We are delighted to be able to bring him to Chelsea and add such a talented young individual to our squad for the new season and beyond.”