Back at the club after a successful loan spell with Al Ain, the 29-year-old former Saudi Arabia international has scored three goals already this season but is currently struggling with an ankle injury.
He is joined in the treatment room by Khalid Al Kaabi and, with Sultan Al Beshi suspended, Kombouare has not got strength to pick from.
The former Paris St Germain coach wants his players to establish an advantage in the first leg ahead of the return fixture in Riyadh, though, saying: "It is an important match as it is the first leg of a knockout game.
"Over these two matches we will have to play very well to keep our chances alive of continuing in the competition."
Speaking on the AFC's official website, he added: "We are ready, even to play a very strong team, even though we have injuries.
"We also have one player who is suspended. But we have players who can take his place."
Wesley and Yoo Byung-soo are in line to replace Al Qahtani.
In another last-eight tie, Adelaide United take on Bunyodkor in what will be the sixth ACL meeting between the two.
Having already met in the group stages, the sides are more than familiar with each other, and Adelaide boss John Kosmina said: "There is a bit of history between the two clubs, not just in the last few months either, it goes back a few years.
"So hopefully that'll work in our favour, especially having the game at home, I think that helps a hell of a lot."
The other quarter-final ties pit Sepahan against Al Ahli and Al Ittihad against Guangzhou Evergrande.
Wednesday's AFC Champions League Quater-final First Leg Fixtures
Adelaide United vs Bunyodkor
Ulsan Hyundai vs Al Hilal
Sepahan vs Al Ahli
Al Ittihad vs Guangzhou Evergrande