Green has started England’s last three internationals, but faces competition from David James and Ben Foster.
“The manager has said he is taking it on club form, who’s playing well and who is training well,” the 29-year-old said in the Daily Mirror.
“There is stuff you can control, and stuff you can control, and the thing I can control is how I play for West Ham.
“I am thinking about going to the World Cup as England’s No.1.
“There is no point turning up if you think you’re going to be understudy. There is no point turning up not to play.”