The pair played together at Rangers.
Asked if Jelavic's transition to the Premier League offered him confidence, he said: "It does. I've got confidence in my own ability but know I'm going to have to work as hard as I can to first of all impress my team-mates and manager to get a place in the team.
"But I'm confident I can contribute and be a success at the club. It's a great platform for me."