Barely two months after his impressive Test debut, the young Yorkshireman is busy establishing himself in both limited-overs formats - and after just seven one-day internationals, his statistics are envious. The 22-year-old's third half-century in six innings - a career-best, unbeaten 79 - helped England to a series-levelling victory over New Zealand in Napier.
Thorpe acknowledged the tough competition for places which appears inevitable after the return of the rested Kevin Pietersen. "It's great to have a world-class player who can come back into your side," he said.
"I always think competition is very important at this level, and to have young players putting senior players under pressure is a good thing as well - because then you get the best out of those seniors. If England want to be competitive in all three formats, then we need that depth."
Famed game-changer Pietersen will surely be back somewhere in the top four, come what may. But if Root is to be accommodated too, others may be vulnerable. Thorpe, long an advocate of Root's potential, has been impressed all over again with his most recent performances.
"Joe's a quick learner. He's got a good temperament, good character and he's a good player," said Thorpe. "But it's early, and I think there should always be an edge of caution with young players."
Root is not likely to become flustered at the first sign of the going getting tough, though. Thorpe added: "I think he's a pretty level-headed bloke, which is important, and I think he's improved a lot in the last six months. At the moment, it's all gone pretty well for him. He seems to have embraced the environment, and fits in very well."
Root has already demonstrated his range of shots, invention and resourcefulness in limited-overs cricket. His slight frame, however, means he has yet to convince he can hit with the power of so many of England's new breed of batsmen.
Thorpe is nonetheless optimistic Root will continue to address that issue in time. "His power has improved within the last year alone. He's physically stronger than he was a year ago, and if you go back 18 months there wasn't that much of him.
"But he always had a good cricket brain. That's what I sensed about him as a batsman; he has good awareness, and that's what half the battle's all about - when to play certain shots. His range of strokes is improving and he's got a good head on his shoulders."