Townsend played superbly on his England debut, scoring a goal in England's 4-1 victory over Montenegro.
His pace and trickery caused the Montenegro defence problems all night and he capped his performance with a stunning 25-yard strike.
Walker hopes Townsend will be in the 23-man party should the team qualify for the finals in South America.
"Yes, I think (he could make the squad). I hope (so)," the Spurs right-back said. I hope this is just a stepping stone for him to showcase his talent and go on to do big things.
"Don't forget he has had to bide his time to get a place, he hasn't just walked into the team, but I just hope for him that he carries on putting on performances like that and we get to where we want to be in the summer."
"He is a nightmare," Walker said. "He eats, sleeps and breathes football.
"He is really confident and you could see that against Montenegro. He just wants to get at players. As a defender you don't want a right winger who is left-footed running at you, it's dreadful, and he is confident to go either side.
"I told him at half-time that he was going to score," Walker said. "I just sensed he was going to do something. He was on fire.
"He was getting at people, but I didn't think it was going to be such a good goal - especially with his right foot as well."
Walker will watch the must-win game against Poland at home after he picked up a second yellow of the qualifying campaign for a petty pull of Stevan Jovetic's shirt.
The former Sheffield United defender, who was making his ninth international appearance because of an injury to first-choice Glen Johnson, admits he made a mistake but is sure either Phil Jones or Chris Smalling will perform well in his place.
"It was a stupid foul, and this is a massive learning curve for me," Walker said.
"We have strength throughout the squad so whoever comes in will do fantastically well and hopefully we will get the win we need."