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. They were once a part of the world's deadliest attacking trio, along with Luis Suarez.
Real Madrid reportedly aim to sign Paris Saint-Germain star Neymar by the summer of 2019.
But his compatriot Ronaldo believes it was a downward move in sporting terms.
During a recent interview with former Brazil global Zico, Ronaldo admitted that he was surprised by Neymar's choice, and feels it was a step in the wrong direction.
'But there are challenges that everyone seeks.
Neymar continued his wonderful form on Wednesday night, scoring against Amiens as PSG reached the last four of the Coupe de la Ligue.
"Sportingly, the decision is a step back", he said.
This weekend might provide a sterner test for PSG as they take on Nantes, managed by former Leicester boss Claudio Ranieri, in Ligue 1.
It's understood Real Madrid are seriously considering making an offer to bring the Brazilian superstar back to Spain, but the La Liga giants will come up against stiff competition from United.