Jelavic registered eight times last term but Gray, recalling his own previous experiences, is expecting the 27-year-old to emerge from his barren spell as an improved player.
"It was his [Jelavic's] second season in the league and he did struggle a bit but I'm hoping that second season will make him a better player," Gray told evertonfc.com. "I'm hoping he will be stronger for his experiences.
"In fairness to him, he was still getting in positions to score goals but it just wasn't happening for him. You could see his confidence had taken a dent. Strikers are very much confidence footballers and if your confidence is up then you will normally score.
"When I was with Everton - during the Championship winning season - I went 10 games without scoring. It was a real frustrating time and although we were winning games, I couldn't quite get a goal.
"I got a couple away at Leicester when we beat them 2-1 [in February 1985]. It was a big game for Everton and then I went on and got another 10 in the remaining games. You do get spells like that."