Kovacic: Chelsea and Sarri believe in me
Chelsea signed Kovacic on a season-long loan from the LaLiga giants as part of the deal that saw goalkeeper Thibaut Courtois go the other way.
Kovacic, who made five appearances as Croatia made it to the World Cup final, came on to make his Blues debut in Chelsea's 3-2 win over Arsenal.
And, having helped Sarri's side maintain their winning start to the season, Kovacic revealed he is thrilled to be working under former Napoli boss Sarri.
88% - Among players to attempt 30+ dribbles in La Liga in 2017-18, Mateo Kovacic's 88% dribble success rate was the best of any player in the competition. Talent. pic.twitter.com/kK0N3zOeuc
— OptaJoe (@OptaJoe) 9 August 2018
"I am happy because of victory, the most important is that team played good," Kovacic told Sport Klub TV.
"I feel fine, I miss rhythm but I just joined the team. I am working fine and improving.
"It was important for me after three years without continuity of play in Madrid, to find a team and coach that want me, and that happened in Chelsea.
"The club who wanted me and the coach that believes in me. That is what I need.
"Sarri knows me for a long time and I watched a lot of his matches. He loves to play, the team is great, with a lot of big players. I don't expect it to be hard for me to adapt."