The 22-year-old has made 52 appearances across all competitions since joining from Ligue 1 club Lens in January 2025, and he won a domestic cup double in his first full season.
The Uzbekistan international has seen his role elevated at the start of the 2026/27 season, after the summer departures of John Stones, Manuel Akanji and Nathan Ake, and Viana is confident he's on the correct development path.
"When we bought him, we all knew about his physical attributes," Viana told an interview on City's website.
"We all believed he could be a really important player for us.
"We didn't think it would be so soon, because he was so young, and had only been playing in France for a really short time.
"We've been really, really happy with him. He's still developing and learning, but I know for sure he will be one of the best centre-backs in the world in the next five or six years."