Surrey opener Stoneman, 30, was all set for a Test debut the moment a 13-man squad was unveiled after England dropped his struggling former Durham team-mate Keaton Jennings following a recent 3-1 home Test series win over South Africa.
Stoneman apart, the team is the same that beat South Africa by 177 runs in the fourth Test at Old Trafford earlier this month.
Warwickshire all-rounder Chris Woakes, only recently fit following a side injury, misses out on the chance to play in the first day/night Test in England, despite the match being played on his home ground.
And there was no place either for uncapped Hampshire leg-spinner Mason Crane.
The in-form Toby Roland-Jones kept his place as third seamer ahead of Woakes, with Stoneman the 12th man to partner Alastair Cook at the top of the order since former captain Andrew Strauss retired five years ago.
"Chris Woakes and Mason Crane are the two guys who will miss out," Root told Sky Sports at Edgbaston on Wednesday.
"I think it's a great opportunity for the rest of the guys to experience a pink ball Test match for the first time and we're really excited."
Root said Woakes needed more time to regain full match fitness.
"He will have definitely wanted to play here but with the lack of game time he's had, it felt like another week of loading up on overs making sure he's absolutely ready coming back from a serious injury is important," star batsman Root said.
"That's where we're at at the minute and I think Toby deserves his opportunity."
Turning his attentions to Stoneman, Root added: "He's obviously got a huge amount of runs under his belt, this season in particular, and in previous seasons as well.
"He's got a well-rounded game, he's a bit more experienced having played a lot of county cricket and I'm excited to see him hopefully take his opportunity."
- 'Set the world alight' -
But with an Ashes tour on the horizon, Root refused to say how long Stoneman would have to make his mark.
"Who knows. Ideally you want someone to come in and set the world alight and their career move forward from there.
"I'd like to think he would get a very good opportunity and some good game time with England.
"Of course you want it (the top order) to be settled. You never want to go into any series with the guys out of form or under pressure but that's one of the challenges of Test cricket and generally as a side we've responded quite well to that in the past.
"This is a great opportunity for him (Stoneman) to go out and show everyone how good a player he is."
Most England players' experience of playing under lights with a pink ball extends to a single round of County Championship matches earlier this season.
"There are obviously different challenges it brings, different times of the day to what you would normally expect with Test cricket," the 26-year-old Root said.
"It's ultimately still the same fundamentals of cricket and you just need to make sure when those difficult periods crop up we respond well and we respond quickly.
"It will be interesting to see how the week pans out."
The Edgbaston test is the first of a three-match series.
First Published: August 16, 2017, 6:48 PM IST