Both have been defensive rocks for City for several years, but a mixture of injury and positional tweaks mean it has become something of a rarity – particularly this season – to see them alongside each other, though they were both in the back four during the 3-1 win over FC Copenhagen.
Onuoha feels they have so many different attributes, that together they are as good as any partnership in world football.
“They complement each other so well,” said Onuoha.
“The way they view defending, being committed, composed, and leading from the back. It’s good to see them both available again.
“To see Stones and Dias, it’s the nostalgia and the good memories, but for City, any centre back pairing brings that feeling.”
Paul Dickov believes the return of Stones is key to City’s quest for silverware on three fronts, believing the England star to be the very best at advancing into central positions.
“We didn’t win many away games in the Champions League last season and the season before, we don’t really go gung-ho and all-out attack,” said Dickov.
“So, it didn’t surprise when Stones stepped into midfield.
“He’s the best player in the world at doing that. In fact, he’s the only English player in the league who can do that.
“We’ve looked so solid away from home and did again against Copenhagen because we have proper defenders who want to defend.”
Steph Houghton is hoping Bernardo suffered no more than a l knock against Copenhagen after being caught full-on at the top of his foot by a clumsy challenge.
The Portuguese was substituted not long after, but Houghton says he is integral to everything City do.
“Bernardo, he’s an amazing player,” she said.
“On the right or in midfield, him and Foden can swap, he’s experienced and takes games by the scruff of the neck.
“He brings energy to the team and sets the tempo of the press.
“Pep is being clever with how he is rotating the team, he’s able to rotate quality with quality. That Champions League experience is vital at this stage.”
Jack Grealish was also forced off with what Pep Guardiola believes to be a muscular issue.
The England winger had been excellent in the opening exchanges and Shaun Wright-Phillips and Onuoha are hoping he makes a swift return.
“With Jack, I always say he’s likely to play in the Champions League because he keeps the ball well and retains it and wins fouls when we need it,” said Wright-Phillips.
“This is the business time of the season. Whoever steps into the team needs to show the manager that they’re there to stay and Jack was doing that”
Onuoha added: “He’s good at keeping possession, he sort of sets the tempo at times in games, too.
“Pep really trusts him to do that in Europe. It was great to see him back in the team. When he’s healthy and in good form, then what a player to have.
“Let’s hope he’s not out too long.”