Chelsea have signed Mateo Kovacic on a five-year deal from Real Madrid.
The midfielder initially moved to Stamford Bridge on loan last summer, helping the Blues to win the Europa League in May.
He has now completed a permanent move, with the Blues expected to appoint Frank Lampard as their new manager in the coming days.
Kovacic told the club's official website: "I really enjoyed my season on loan with Chelsea, I feel comfortable at the club and like London and the Premier League very much. I am very happy to be able to join permanently.
"We had a successful year, winning the Europa League and I hope I can make a big contribution in the coming seasons."
The 25-year-old - who had been at Madrid since 2015 - made 51 appearances in all competitions for Chelsea, who finished third in the Premier League, but did not score.
Meanwhile, Juventus have completed the signing of free agent Adrien Rabiot.
The 24-year-old's contract with Paris St Germain expired on June 30 and Juve have moved quickly to add the midfielder to their roster.
Earlier on Monday the Serie A champions had tweeted a series of pictures showing Rabiot arriving at the club and undergoing a medical.
His last game for PSG was on December 11. He was not considered for selection by boss Thomas Tuchel after it became apparent he was not going to sign a new deal with the club.
Last year he made himself unavailable for the World Cup after being left out of France's 23-man squad and was subsequently criticised by French Football Federation president Noel Le Graet for the decision.
Rabiot is Juve's second free transfer signing of the summer, following the arrival of fellow midfielder Aaron Ramsey from Arsenal.
