Jordan Pickford started in the victory over Nigeria on Saturday and is widely expected to be England's first-choice goalkeeper at the tournament, particularly after he was handed the number one shirt.
However, Butland remains determined to give the best account of himself possible as he looks to force his way into the reckoning and will seemingly be given a chance to stake his claim on Thursday night.
"Until there is an official announcement whereby I'm not playing then I will keep fighting and I'll will keep pushing and staking my claim to be the No 1, regardless of shirt number," he insisted.
"We'll see what happens. I'll push myself as hard as I can and push the others as hard as I can as well."
England get their World Cup campaign underway against Tunisia on June 18.