The veteran Wales midfielder spent two seasons at the Parisian club from 2013 to 2015 and a number of the players he encountered at that time in France are now on the cusp of European glory.
Roberts had a special mention for Vakatawa, the Fijian who is now viewed as one of the world’s best attacking players at the age of 28 with Racing. He has also become a regular France national team player.
Speaking on the RugbyPass Offload, Roberts said: “I played there with Johnny Sexton, Mikey Phillips arrived the year after me. He was a good laugh. The French guys? I couldn’t understand what was going on half the time because they all operate in French.
“But you look at someone Teddy Thomas, he is horizontal. Like that guy doesn’t even need to try to look good, if that makes sense.
“I remember Virimi Vakatawa being this academy kid who couldn’t speak French, couldn’t speak English, dropped into training and carved everyone up. The lads said, ‘Who the hell is this guy?’
“We’d be doing backs unit sessions and this guy would be just making us all look like idiots. His footwork and his lines. He was young at the time and here is now, for me one of the world’s best players. It’s brilliant to see how far he has come.
“There is a core of that group still there. Henry Chavancy, club captain, is a cheeky chap. He has been there since he was an academy lad. Juan Imhoff is a bit of a joker but one of the best wingers in world rugby and a fantastic finisher.
“Max Machenaud at No9 who has had to play for his position with Teddy Iribaren who is a wonderful scrum-half as well. They have just added depth. And Camille Chat, Jesus Christ, that guy has probably trebled in size since I last saw him. An absolute menace as a ball carrier and over the ball – and he now plays like a back row.”