Belgium international Tielemans, 28, came off in Sunday’s 2-0 win at Newcastle with an ankle injury and checks have confirmed he is unlikely to return until April.
“Tielemans is eight to 10 weeks out,” said manager Emery on Wednesday. “Kamara is not going to play this season. McGinn is six to eight weeks out.
“After those updates of those players we need to manage the centre midfield in the matches we are going to play.”
Kamara has had surgery on his injured knee, having come off in the FA Cup win over Tottenham earlier this month.
Another midfielder, Ross Barkley, who last played in November, is “coming back in a few days”, Emery said.
Defender Andres Garcia is set to be out for three weeks with a hamstring injury.
Striker Tammy Abraham joined Villa in an £18.5m deal from Besiktas on Tuesday and winger Leon Bailey has returned after spending the first half of the season on loan at Roma, while forward Donyell Malen signed for Roma earlier in the window.
Villa host Red Bull Salzburg on Thursday in the Europa League at Villa Park having already qualified for the knockout stage.
Despite the injury problems, Harvey Elliott’s situation at Villa has not changed.
Villa do not want to pay the additional £30m to make his move from Liverpool permanent. They would be obliged to pay that fee if he makes 10 appearances.
The attacking midfielder has played five times since his summer loan from Anfield but has not featured since October, although he was on the bench against Newcastle.
“With Harvey, it is not changing,” Emery said. “We have our idea. I spoke with Harvey clearly. I said before that he is a fantastic guy.
“He was on the bench against Newcastle on Sunday and was there if we needed help from him, he was ready to play.
“Tomorrow he is in the squad as well but it is not changing the situation he has now.”
