England beat Tunisia in their opening Group G game and know that a victory over Panama – as well as Tunisia failing to beat Belgium – would secure a place in the last 16.
On the other hand, Panama need to avoid defeat to England when the two sides meet on Sunday if they are to retain any realistic hope of reaching the next round.
But Walker says Panama will match England physically and that Gareth Southgate’s side are prepared to alter their tactics slightly to deal with Sunday’s opponents.
“We’ve seen a few clips and we know they’re a physical side,” he said. “Panama are probably more direct (than Tunisia) so we’ve had to change our game-plan a little bit and think of the threats they’re going to cause us.
“It isn’t going to be a walkover. It’s going to be a tough task but if we just concentrate on ourselves we should be fine.
“They’re fighting for their lives to stay in this competition and if we get the victory we want, they’re out.
“They need to worry about us more than we need to worry about them. We’ve got key men in key areas who can go and get goals at any time.
“So if we keep to the style we’ve been playing throughout the build-up to the tournament I think we’ll be fine.”