The Brazilian completed his £70million move to Old Trafford earlier this week, ending his nine-year association with European champions Real Madrid.
At 30 years old, the midfielder has won just about everything that you can in European football with three La Liga titles and a staggering five Champions League winners medals to his name.
With United not playing in the elite European competition at present, some may think that a move to Manchester is something of a gamble for a player of his pedigree, but according to Casemiro, some advice from two familiar faces was enough to convince him.
Speaking to MUTV, Casemiro said: "Well, before coming here I spoke to Fred.
"He's a great player and that's why he plays for Manchester United and for the Brazilian national team, which is difficult to get into. So, I have a special relationship with him and of course he's a great player.
"I think he's a player that has good movement. He's very mobile, passes the ball well, he has a good shot on him, he can play with both feet, left or right, he can pass the ball well with either foot. He's a great player.
"I think he'll help me a lot at the club and without doubt it's important for me to have another Brazilian here, too.
"He [Raphael Varane] tells me he's happy. His family is very happy here in Manchester and I feel Manchester United have a great centre-back in him and, as we know, Cristiano is up there as one of the best players in the history of football and I think he'll keep achieving things."
Asked how he would describe himself, the Brazilian added: "That's difficult. I think I'm a player that loves to work hard. A player that gives everything on the pitch, but not just over 90 minutes, in training too, which for me is the most important thing.
"You train as you play and I think, regardless of the scoreline or what's happening on the pitch.
"Of course everyone wants to win matches, win in training, learn in training, but I'm one of those players who wants to go home and know that I've done my job so, that's my philosophy, my mentality and now it's all about giving everything for Manchester United."