Stones started alongside Aston Villa’s Ezri Konsa in England’s latest friendly and could be given the nod ahead of Manchester City team-mate Marc Guehi for the Croatia game (Wednesday, 21:00 BST).
Stones played just 439 minutes of Premier League football in the season just ended, featuring in only 18 games for City across all competitions.
He missed two months with a thigh injury and had to sit out England’s two friendly matches before Tuchel picked his squad because of a calf injury.
But Stones, who announced in April he will leave City this summer, says he has been “fit, pretty much all season”.
Tuchel gave his backing to Stones, picking him ahead of Harry Maguire and Levi Colwill, by saying he remains a “big part” of his plans and has “a lot of credit in the bank”.
This will be Stones’ sixth major tournament for England, having helped the side to reach the semi-finals and quarter-finals of the two previous World Cups.
“I love being here and I think that goes without saying,” Stones said.
“But when I got the call off of the manager, I think he saw the kid inside of me, how I reacted it where I couldn’t really control myself.
“It was like the first time, just pure joy coming out of me, and I think that is one of the qualities that he loves – how all of this group can be ourselves as players.”