Rafael and compatriot Anderson spent seven years together at Old Trafford, winning three Premier League titles under Sir Alex Ferguson.
Anderson joined United from FC Porto in the summer of 2007 while Rafael and twin brother Fabio arrived at Old Trafford from Brazilian side Fluminense in 2008.
Despite showing a lot of promise, Anderson left United in 2015 wondering what might have been, having struggled with fitness problems for much of his time at the club.
“We could be on the team coach and pass the services on the motorway and Anderson would jump up impulsively and yell 'McDonald's, McDonald's,'” Rafael wrote in his autobiography The Sunshine Kids - published by The Mirror.
“The guy was crazy, but I love him. Give him a football and he would just play with freedom and sometimes, if he got a good run of games, he could play as well as any player in the league.
“Not only that, but when he was playing well, we were playing brilliant football. He picked up a lot of big injuries and then his problems with eating the way he did started to affect him.
“It was no coincidence that his best form came when he had a lot of games because that was when he couldn't eat so much. I will say something about Anderson – if he had been a professional football player, he could have been the best in the world.
“I'm saying this with all seriousness. I don't know if he ever took anything seriously. He just loved life in such an easy and casual way.
“In some ways that was a quality. It was what made him so popular and one of the most popular players at the club.
“But he would just eat whatever was put in front of him.”
Anderson made 181 appearances in total for Manchester United, scoring seven goals and providing 21 assists.
