I don't think we can say it's the most important game of the Premier League so far. At the current stage of the Premier League each game is as important as the next.
But it's not an issue if he is easily passed as Terry and Zouma will always be there. He's just an extra defensive barrier. It's a very defensive team for sure.
I really don't think he'll be bad sitting just infront of the defense. His issue is covering Ivanovic when he attacks, in that position he won't have to cover anyone, just be an added defensive barrier.
-------------Courtois---------- Ivanovic Terry Zouma Azpi --------------Cahill------------- -----Ramires Fabregas------ Hazard---------------- Willian ------------Costa--------------- Doesn't look to bad to me considering the circumstances.