The 22-year-old has been moved up the batting order to open with Cook in place of Nick Compton for Wednesday's first Test at Trent Bridge.
Despite concerns over his lack of experience, the home side's skipper believes that Root is more than capable.
"He's handled himself in every situation fantastically well since making his England debut," Cook told reporters.
"I can see no reason why he can't handle himself. He's a fantastic young player, yes he's got a huge amount of improvement to do, but I think he'll be fine."
Root made his Test debut for England against India in December.