England have made four changes in the second test against India, with Chris Woakes and Olly Stone vying for the final seamer's place.
England, who won the opening match by 227 runs, have rested James Anderson, while wicket-keeper Jos Buttler will return home, as part of the team's policy to keep multi-format players fresh.
Off-spinner Dom Bess has been dropped, after struggling in the second innings of the first test, while speedster Jofra Archer will miss the match with an elbow injury.
Ben Foakes will substitute for Buttler behind the stumps for the rest of the four-test series, while spin all-rounder Moeen Ali will replace Bess in the match, starting on Sunday.
Veteran seamer Stuart Broad is back, but Woakes will have to compete with Stone to break into the playing XI.
England need to win at least two of the remaining three tests in the series to secure a spot in the inaugural World Test Championship final against New Zealand on home soil in June.
"It wasn't an easy decision," Root says about dropping Bess, who managed four first-innings wickets.
"The message for him moving forward is to keep working at that consistency of his game, delivering that skill time and time again. It gives Moeen a great opportunity to come back with all of his experience."
Moeen's 61st test would be his first since August 2019, after taking a break from this format that year.
Anderson was keen to play on, after a matchwinning spell on the final day last week, but Root justifies the team's rotation policy, saying they had to look at the "bigger picture".
"I think it gives Jimmy the best opportunity to be fit and available for those last two games," Root adds.
"Ideally, if he's available for two of the last three, that's a huge asset for us as a team."
Root says the team will take a look at the pitch at the MA Chidambaram Stadium, before deciding whether Stone or Woakes should play.
"With Stony, we can play with a similar balanced attack, someone that can come in at a high pace, give us a real point of difference in our seam department," he says.
"Or we could go down the road of Woakes, who gives us great control, lengthens our batting and brings reverse swing massively into the game as well.
"So we feel, either way, whichever balanced side we go with, we're going to give ourselves a really good chance of taking 20 wickets in these conditions."
England: Joe Root (captain), Dom Sibley, Rory Burns, Dan Lawrence, Ben Stokes, Ollie Pope, Ben Foakes (wicketkeeper), Moeen Ali, Olly Stone, Chris Woakes, Jack Leach, Stuart Broad.