Manchester City  completed the signing of Croatia midfielder Mateo Kovacic from Chelsea.

The treble winner  announced the 29 year-old has signed a four-year contract at the Etihad Stadium after the clubs agreed an initial fee of £25million, with a potential extra £5million in add-ons, last week.

Kovacic joins Pep Guardiola’s side after five years at Chelsea, where he won the Champions League and Europa League and made 221 appearances.

He is City’s first signing of the summer and his arrival compensates for the departure of captain Ilkay Gundogan, who joined Barcelona on a free transfer on Monday after seven years at the club.

“This is a brilliant move for me and I cannot wait to get started with City," Kovacic said. “Anyone who has watched this team under Pep knows how good they are. For me, they are the best in the world.

“The trophies they have won are clear for all to see, but they are also the best footballing side out there.

“To be joining this squad really is a dream for any footballer. I still have plenty of learning and developing to do, and I know under Pep’s management I can become a better player, which is really exciting for me.

“My plan now is to rest for a few weeks before coming back to Manchester to prepare for the new season. I want to help this club stay at the top and win more trophies.”

Kovacic is a four-time Champions League winner having also enjoyed success in Europe’s elite competition three times with Real Madrid before joining the Blues.

A versatile player, he began his career with Dinamo Zagreb and has also had a spell at Inter Milan. He has earned 95 caps for his country and will inherit Gundogan’s number eight shirt.

City director of football Txiki Begiristain said: “Mateo is an excellent footballer.

“He can play as a ‘six’ or an ‘eight’, has plenty of experience at top-level clubs and he understands the Premier League.

“It was a very simple decision to bring him to City because he has the tactical and technical qualities we are looking for in a midfielder.

“He is someone we have monitored for a very long time and always we were impressed whenever we watched him. I am delighted he is here.

“This is a great signing for this club, and I am very excited to watch what he can do with Pep and the rest of our backroom team.”

Kovacic may not be Guardiola’s only midfield reinforcement this summer, with speculation that the champions have had a bid rejected for West Ham’s Declan Rice.

The England international is widely expected to leave the London Stadium and has reportedly already been the subject of two failed approaches from Arsenal.

It has been claimed City made an offer totalling £90million for the 24 year-old but the Hammers are said to be holding out for a fee of £100million.

City have not commented on the reports.