Fortuné only arrived at the club on Friday following his 90-minute outing for the Hoops against Utrecht in the Europa Cup.
Di Matteo said: "He did a good job for us.
"He's only been here a couple of days and needs time to settle down. We're still trying to integrate him into the team, as we do with all the new players.
"He played a full 90 minutes on Thursday, did a lot of travelling but he was a good outlet for us."