Dons boss Derek McInnes admits he fears the worst over the hamstring injury suffered by defender Ash Taylor in Georgia.
The centre-back limped off in Tbilisi after just 18 minutes of the 1-1 draw with FC Chikhura Sachkhere.
Just three games into the season, the Dons are already suffering a rearguard crisis with half their defenders out injured.
McInnes admits Taylor “will not be back any time soon” and centre-back Mikey Devlin is also out with a hamstring injury.
Both will miss the return leg on Thursday with the Georgians at Pittodrie.
Left-back Greg Leigh has missed all three Europa League ties with an ankle injury.
The summer signing faces a battle to be fit for the clash with Chikhura.
McInnes said: “It is a hamstring injury with Ash and naturally we fear the worst with that.
“I don’t think he will be back any time soon. But hopefully it is not as bad as maybe it could be.
“We have three injured defenders now and we only carry six.”
The loss of Taylor forced McInnes to reshuffle his team in Tbilisi with Jon Gallagher moving to right-back and Shay Logan switching to left-back.
Andy Considine moved inside from left-back to centre-back.
In the second-half winger Ryan Hedges dropped back into the left-back role.
McInnes said: “When you put a squad together you try to get the balance right and you think you have enough at the start of the season.
“It just shows you, as it was last season, when you get three injuries in one area.
“Jon Gallagher can play at right-back and Shaleum Logan has played at left-back before. But I just felt we lost a bit of the rhythm of the team.
“Obviously Ryan Hedges had to play as a more advanced left-back, which gave us a bit more balance.
“We saw the benefit of that in the second half in possession and also out of possession.”
McInnes has only three fit defenders in Scott McKenna, Andy Considine and Logan.
He was confident he had a back line with options and depth, having signed Leigh and Taylor during the summer.
Of the game itself, McInnes added: “We took real charge in the second half and I felt the goal was coming.
“While 1-1 is not a perfect result, it gives us every opportunity next week to try to finish the tie at Pittodrie.”
McInnes hailed Scotland international centre-back McKenna for his “outstanding” contribution in Tbilisi.
He also praised Considine, who is set to partner McKenna in the centre-back roles on Thursday.
McInnes said: “We had some good performances, but I thought McKenna was outstanding.
“McKenna and Andy Considine, as they normally are, were very strong at centre-back.”
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