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Riaz described England's middle order as "fragile" before the first Test at Lord's starting on Thursday.
"It's the same before every series - you generally get a bit of trash talk," said Root, who will bat at three.
"It's getting a bit like boxing now. We will have to wait and see how things develop and see if the plans work."
Boxing is notorious for fighters' pre-match verbal contests aimed at intimidating opponents.
James Vince, who has played only three Tests, and the recalled Gary Ballance will bat at four and five for England when the four-Test series gets under way.
Former England captain Michael Vaughan said Vince should have been promoted to three to enable Root to stay at four.
England vice-captain Root, 25, averages 50.36 in 21 innings at number four and only 28.71 in eight innings at three.
Root, 25, said it is "a great opportunity to bat a bit longer" and that captain Alastair Cook, coach Trevor Bayliss and the selectors gave him time "to get my head around it".
He added: "It's about taking that opportunity for responsibility as a senior member of the side, to lay some good foundations for us to make some big scores."
Nick Compton batted at three for England in the 2-0 series win over Sri Lanka, but announced he was taking a break from cricket after scoring only 51 runs in five innings.
Vince managed 54 runs batting at five against Sri Lanka, his debut Test series.
Ballance has not played for England since being dropped last July, but made 132 for Yorkshire against Middlesex this month in his most recent first-class game.
Root said Vince and Ballance had a "great opportunity" to prove Riaz wrong, adding: "Gary's in fine form - he's just got a hundred for Yorkshire.
"Vincey's a brilliant player. He made his first innings for England in the one-day series against Sri Lanka - he made a brilliant fifty. So they'll take confidence."
Pakistan pace bowler Mohammad Amir will play his first Test since serving a five-year ban and three-month prison sentence for spot-fixing at Lord's in 2010.
England captain Alastair Cook has warned the 24-year-old, who took four wickets in Pakistan's opening tour game against Somerset, to expect a "reaction" from the crowd this week.
But Riaz said: "Mentally he's very strong, and he's very eager to perform.
"The place where it all began, he will perform at that place and make sure his name is reborn."

Greg Allen, 43, of Seacoast Road, Bellarena, County Londonderry, was convicted along with another man for breaching waste and marine laws.
He plans to appeal the sentence, but not the conviction.
Mr Allen said he has lost at least six acres to the sea over three decades.
He estimates that the land washed away could be worth up to £50,000 and said he was trying to prevent further erosion.
The bales of tyres were put in place to protect a motocross track developed on his ground at the edge of Lough Foyle.
Mr Allen said at least 15 neighbouring farmers are suffering the same problem as him with coastal erosion.
And he questioned why farm land further along the coast was being protected with proper sea defences built and maintained out of the public purse.
"The more ground you lose, the more our income drops," he said.
"If a farmer loses ground for a roadway, he's compensated. We're not, and we're not being allowed to do anything about it either."
Mr Allen said he has been told that to put in a properly licensed sea defence along 100 metres of shoreline would cost up to £90,000 - if it were to be approved.
He must now remove the tyres, which he said will cost him more than £15,000.
Baled tyres have been trialled as potential sea defence material by the authorities in England.
It has not become a mainstream practice.
England batsman Joe Root said cricket is becoming like boxing as he dismissed Pakistan bowler Wahab Riaz's "trash talk".
[NEXT_CONCEPT]
A farmer given a suspended four-month prison sentence last week for having 20,000 tyres along the shore fronting his farm, has said he was trying to protect his land from coastal erosion.