The Croatian forward has scored six goals in 25 appearances for the
sixth-placed Toffees this year, compared to his 11 strikes in the final 14 games of the last campaign.
"I don't really have any great thought on it," Moyes is quoted as saying by The Guardian. "I just hope he can find his way again.
"It is always confidence in things like this but sometimes you don't realise that until you come back into form. How we finish the season will have a lot to do with how Nikica Jelavic performs and scores."
Everton travel to Norwich City in the Premier League on Saturday.