Controversial spinner Monty Panesar and three uncapped players - batsman Gary Ballance, all-rounder Ben Stokes and seamer Boyd Ranking - were on Monday named in a 17-man squad containing few surprises and the bulk of the side that claimed a 3-0 home Ashes win last month.
Experienced batsman Nick Compton was a notable omission, with Ballance and top order specialist Michael Carberry favoured by selectors.
Harris said Australia would need to be ready for whoever fills the order but relished England's apparent batting dilemma around the front five ahead of the opening Ashes Test at the Gabba on November 21.
QUICK SINGLE: England announce 17-man Ashes squad
"There's obviously a bit of doubt there - which is good, because that obviously keeps them unsettled and keeps a bit of doubt in their camp," he told reporters on Tuesday.
"But it doesn't matter who it is, we've just got to make sure we research them and know what they do when they come out and make sure we know where to put the ball.
"We put pressure on them and that's why I think they cracked (last Ashes series). If we keep doing that, hopefully we'll get the same result."
Harris, Australia's leading wicket-taker in England, said consistency was key to toppling England's big hitters at home, naming Ian Bell as the biggest threat.
"We've obviously got to get better at bowling to Bell. We gave him a little too much width," he said.
"He's obviously the man who controlled and came in at times when they were in trouble and did well.
"So if we can limit him down and keep doing what we did to the rest, hopefully we'll be bowling for a lot less than we did."
Harris dismissed suggestions the inclusion of some very tall quick bowlers - including Chris Tremlett and Steven Finn - was a deliberate strategy by England.
"I don't think it's a ploy. I think they're their best bowlers at this time and they obviously have to pick them," he said.
"They're their front-line bowlers.
"We saw Tremlett bowl here last time, he bowled very well. And obviously Finn - he didn't have a great time in England but with their height and their decent pace, they're obviously challenging."
Harris steered clear from commenting on Australia coach Darren Lehmann's claim on British radio that England were a "dour side".
"He can take care of all the controversial stuff," Harris said with a laugh.