Key midfielder Wanyama will miss the final group game with Spartak after picking up a booking in the defeat to Benfica.
Kayal, who has struggled to hold down a regular place in Neil Lennon's side this term, is hoping to get the nod to replace Wanyama and help Celtic qualify for the last 16 of the Champions League.
"Losing Victor is massive and bad for this game," Kayal told the Daily Record.
"He is an important player but at the same time we have a big squad and everyone helps out to provide cover.
"We all work as a team and do what we can to do our job and we all saw that against Barcelona.
"We lost a lot of players but we proved we have a big squad who are all capable of doing well.
"I am training hard so I am ready whenever the gaffer picks me."
Celtic need to better the result of Benfica, who face Barcelona at the Camp Nou, if they are to reach the knockout stages and Kayal admits it will be massive occasion at Celtic Park.
"We usually say every game coming up is the biggest game of our season and that is what I normally believe," added Kayal.
"We are in a good position in the group and we know what a good result will mean.
"If we win at Celtic Park and Benfica draw or lose to Barcelona it will take us into the last 16.
"It's a dream for everyone here as we all want to qualify so it's going to be a massive night."