Skipper John O'Shea reckons that the Ireland team will sorely miss the midfielder's talents in the crucial fixture which takes place in Dublin in October 8.
"We saw at different stages he was controlling the tempo – even looked at one stage he was going to breakthrough. He's crucial to the team and we'll need someone to come in and take his place," said Sunderland defender O'Shea after the 1-0 win over Georgia on Monday.
"We know how important a role he plays for us. It's one of those things when people talk about what he does for the team.
"He's an unsung hero. He does all the dirty work in the three-man midfield. At one stage in the first half he had two great tackles and kept the ball going for momentum. I've played with Whelo a long time now so I know how good a player he is."