The two players have joined Manchester United captain Nemanja Vidic on the sidelines and will miss the match with Northern Ireland on Friday, but could be fit for the visit to Estonia on March 29, coach Vladimir Petrovic said.
"It's never a pleasant situation when you have to reshuffle the team but we have able replacements if they don't recover," Pertrovic, whose side desperately need to kick-start their qualifying campaign, told reporters on Monday.
"We hope that some of the injured or at least the walking wounded will be fit for the trip to Estonia."
Birmingham striker Nikola Zigic is also doubdtful with a groin injury, leaving Petrovic with few options up front after Dragan Mrdja had earlier suffered a season-ending injury while Danko Lazovic quit international football last week.
The Serbs, who are fifth in Group C with four points from as many games, entertain Northern Ireland behind closed doors as they serve a one-match ban for a riot their fans caused during last October's game in Italy.
Having attacked their own team bus before kickoff, Serbian ultras forced the match to be abandoned after six minutes when they threw flares at home fans, players and police and also clashed with riot police outside the stadium.
Wolves midfielder Nenad Milijas, who played a Belgrade derby for Red Star against Partizan behind closed doors before he moved to the Premier League, said the lack of fans in Red Star's 55,000-seat stadium would be a setback for Serbia on Friday.
"Empty terraces are an eery sight, just as it's a scary feeling to play when we can hear ourselves on the pitch," said the 27-year old playmaker.
"But Red Star won that game 4-1 and I really wouldn't mind the empty terraces if we could have the same result against Northern Ireland."
Italy lead the group with 10 points from four games, followed by Slovenia on seven and Estonia on six points. Northern Ireland have five points from three games, while bottom team Faroe Islands have one from five.
