The Dutch manager is under pressure following United’s lowest-ever Premier League finish of eighth last season, as well as two losses in their first three games of the current season.
Additionally, Ronaldo questioned Ten Hag’s mentality after spending two stints at the club before departing to play for Al-Nassr in Saudi Arabia.
He said, “The coach says they cannot compete to win the [Premier] League and Champions League,” in the Rio Ferdinand Presents podcast, external, which airs on Thursday.
“You cannot claim as Manchester United’s coach that you won’t put up a fight to win the league or the Champions League.
I want Manchester United to be the best team they can be, and that’s what I want for myself as well.
“I adore that club. I’m not the type of guy who lives in the past.”
Before moving to Real Madrid in 2009, Ronaldo won three Premier League titles, the Champions League, two League Cups, an FA Cup, the Fifa Club World Cup, and the Community Shield during his six-year first stint at United.
After rejoining United from Juventus in August 2021, he made 346 appearances for the team and scored 145 goals in all until moving to Al-Nassr in December 2022.
In a contentious TV appearance just one month prior, Ronaldo had claimed he was being “betrayed” and driven out by presenter Piers Morgan.