Jorginho has said Chelsea have received a top class player and person in Kalidou Koulibaly.
The 31-year-old defender, who represents Senegal, has joined from Napoli.
Italy international Jorghinho played with Koulibaly in Naples.
“I am so, so happy he’s here,” Jorginho told the club’s website.
“As a player, he’s a brilliant defender – fast, strong and he has so much quality on the ball with both feet. He’s also a real leader.”
He added: ‘We’ve stayed in contact since I left Napoli. He speaks better English already than I do so that will be good for him to help settle in!
“It’s going to be really easy for him because of the person he is. Of course we will help him to make it maybe a bit easier for him to get involved with the team-mates and everything, but even if he didn’t know us it would be easy for him because he’s such a good guy.”