Roy Hodgson's side would guarantee their place in next summer's World Cup qualifiers with wins in both games, but anything less than six points would leave a trip to Brazil under threat.
Gerrard has admitted that failure to qualify would be a "catastrophe" for the Three Lions, conceding that the players feel the weight of expectation from expectant England supporters.
He told The Mirror: "This is as critical a week as English football has known for a long time. There's a lot of expectations, from the fans, the media and in and among the group as well.
"Everyone wants to be at this World Cup. So it is very critical. We need to go out and deliver. It doesn't come much bigger than this. We all know how much the supporters want it.
"I don't like using the word 'disaster' or 'catastrophe', but the Brazil World Cup is going to be so big. Individually and collectively, we all want to be there."