Rangers will be without Kirk Broadfoot and Vladimir Weiss for the rest of the Scottish Premier League campaign through injury.
Defender Broadfoot was recovering from a foot injury that has kept him out since December but has suffered a hairline fracture of his heel.
And winger Weiss has played the last game of his loan from Manchester City after a scan confirmed a broken foot.
Rangers manager Walter Smith said: "We'll lose them for the season."
Weiss has not played since 20 March and has already returned to his parent club.
But Smith, who only named six substitutes for Wednesday's 1-0 win over Aberdeen, had hoped that Broadfoot would help bolster his squad.
"He's got a hairline fracture of the heel after just coming back," he said. "He has not had any luck the big yin."
Smith reported that midfielder Lee McCulloch and defender Madjid Bougherra were "there or thereabouts" in their return from injuries.
"It is just a question of whether we are willing to take a chance, but hopefully in the coming games we will have them back," said the manager.
"We are a little bit short in terms of defenders."
Smith thought there would be no lasting problem from knocks suffered by Jelavic and Steven Whittaker during the match at Pittodrie.
The Rangers manager was not surprised by the quality of the striker's spectacular overhead kick that won the game.
"It is his speciality when it is up and a volley down," said Smith.
"He has had a couple of them this season and is doing it in training on a regular basis."
Smith was delighted with the victory over the Dons that edges his side back to within two points of leaders Celtic.
"This was a terrific result for us. It keeps us going and will stand us in good stead," he said.
"When you look at the results we've had up here, they've not always been the best, so it is a big boost for us to win here."
Smith recognised that threat Aberdeen have caused Rangers in the past.
"Aberdeen are always a difficult team for us to come up against here and that proved to be the case," said Smith.
"They started a little bit better than we did.
"Then we settled in the game and played well in the middle part of the first half especially and got a fantastic goal by Jelavic.
"The second half was always going to be tough.
"Aberdeen, when I look at them over the season, they have changed a great deal.
"They have good attitude about them and they fought hard and there were a few near things near the end."