Eyebrows were raised when Neymar left Lionel Messi and Barca in a world-record deal after French powerhouses PSG activated the Brazil international's €222 million buyout clause in August.
The Brazil worldwide has enjoyed a blistering start to life in the French capital, scoring 20 goals and bagging 14 assists in 20 games in all competitions so far.
But Ronaldo believes his decision to play for PSG is a bad career move.
"Sportingly, the decision is a step back", Ronaldo told ex-Brazil global Zico in an interview via YouTube.
PSG qualified for the semi finals by defeating Amiens 2-0 while Rennes defeated Toulouse 4-2.
And he'll be hoping to get on the scoresheet again when they take on Claudio Ranieri's Nantes this weekend.
I personally agree with what Ronaldo had to say about the player.
Reported by AS, the 41-year-old said: "Sportingly, the decision is a step back".
The Brazilian is in his prime, he is both young and experienced, and has already won a lot and can even win more. But a move to Paris Saint-Germain is surely a step back.