Ronaldo has appeared agitated with teammates on the pitch and a recent report by the Mirror suggested there is discontent off it.
The report claimed Ronaldo and club captain Harry Maugire were embroiled in a power struggle over who should wear the armband after the England international’s downturn in form.
But Rangnick quashed the captaincy rift rumours in his press conference before Sunday’s game away to rivals Leeds.
“This is absolutely nonsense – I’ve never spoken with players about captaincy,” Rangnick said.
“It’s never been an issue with me. Harry is our captain and will stay our captain.”