Jelavic has failed to score in his last seven Barclays Premier League games and was once again ineffective against Bolton Wanderers, with his 79th-minute replacement Johnny Heitinga the one to summon the injury-time winner.
Moyes said: "I want to give him every opportunity to get it right and I felt this was an opportunity.
"I have been looking at it and I will need to look at it again. Obviously I want to give him every positive I can to show I trust him by playing him in the team.
"I would love to (bring another striker in) but I would be very surprised if I did."