The Croatian World Cup finalist moved to Stamford Bridge on loan last summer and was a regular in our midfield, helping us to a Europa League triumph and a third-place finish in the Premier League.

Kovacic has now signed a five-year contract and will be a member of our squad for 2019/20.

Kovacic said: ‘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.’