Former Chelsea manager Roberto Di Matteo admits he's a fan of Kalidou Koulibaly.

The Senegalese defender made his first outing in Chelsea colours in last night's pre-season defeat to Arsenal, with his performance the main positive from a disappointing night.

"Koulibaly and (Raheem) Sterling and two brilliant signings," said Di Matteo to the club's website. "I think they are going to be very important for the team this season and for the future.

"They are two players that I think will have a big impact at the club and I'm sure the coach knows them very well in terms of how he wants to utilise them.

"I think they will bring a lot of quality into the side, for sure.

"Being Italian, I watch Italian football quite a lot and with regards to Koulibaly, he's a top-class player.

"He will bring physicality, which you need in the Premier League, but also he has a lot of technical ability and he has the tactical awareness that you see from the Italian sides in Serie A.

"So I think he be a good signing for Chelsea. I feel like we are getting a top player who is in the prime of his career, so I can only see positive things."