Curran, the 22-year-old son of former Zimbabwe international Kevin, will replace the injured Craig Overton (who has been diagnosed with a fractured rib) in the England side. That means Curran will make his debut in the Boxing Day Test in front of a first-day crowd that could exceed 90,000.
But Root, the England captain, is confident that Curran will not be intimidated by the atmosphere of the hostility of the opposition. And, combined with his excellent fitness record and ability to withstand a demanding workload, it was enough to see him win selection ahead of more experienced seamers such as Jake Ball and Mark Wood.
"Tom offers a lot," Root said. "He's a real competitor. He does get the ball to move around a bit - he's skilful - and he's always in the contest. He has a similar work ethic to Overton. He's always wanting to get in the contest and you know that he will give you everything.
"He's a feisty character. One thing that really stands out to me is that at no point will he hide away from a challenge if it does become very hard he'll give it absolutely everything."
While Wood is understood to have assured the team management over his fitness, Root felt his selection on what is expected to be another very good batting surface "might have been a risk."
"The fact that Wood is not necessarily 100% fit and he hasn't played a huge amount of cricket came into it," Root said. "He might have been a risk going into this game. It was a tough call."
And while Root still expects the MCG surface to be "slow and dry towards the back end" of the game, he felt some watering of the pitch on Christmas Eve might have counted against the inclusion of the legspinner Mason Crane.
"He's been very impressive," Root said of Crane. "He's close to playing because of the way he's gone about things in practice and in the warm-up games. But looking at that surface, we wanted something different, though it might be that if it does offer spin further down the line. It wasn't an easy selection."
Curran was not an original member of the tour party - he was added to it when Steven Finn was forced home through injury - but has clearly risen above Jake Ball in the management's view as the trip has progressed. While he has not taken a five-wicket haul in first-class cricket since September 2015 (and he has never taken one in Division One of the County Championship), he does play most of his home cricket on a relatively unresponsive Oval surface. He is likely to bat at No. 9 - he averages 17.70 and has a top first-class score of 60 in first-class cricket - and scored an unbeaten 77 in the warm-up match at Richardson Park .
"This match is a big test of our character," Root said. "But that's one of our strengths. That hasn't let us down in the first three games. We have been out-skilled and not good enough when it really mattered.
"That's our big challenge this week. We need those big scores that get you ahead of the game and into strong positions. And we need to create 20 chances and take them to win the Test match."