Rangers boss Smith delighted with Jelavic scoring form
Jelavic struck twice in victory over St Johnstone.
He has 10 goals for the season so far and Smith is confident he will see a return on the £4million Rangers paid for his services last summer now that his injury problems are in the past.
He said: "It was obviously a problem for him and for us as well that we lost him.
"I felt we were signing someone who could get us a lot of goals and I think he has shown that he can do that.
"But the three months that he was out have been a major disruption to his season.
"It's always difficult for a player to come back in and gain the required sharpness.
"He's getting there and will probably be reaching his peak as the season is coming to a close.
"For ourselves, we are just happy that he is back in and scoring goals.
"He could have had a hat-trick in the last couple of home matches and we just need to hope he keeps that going."