Marcelo has claimed that "a fit Casemiro" is "very important" for Real Madrid ahead of the Champions League final against Atletico Madrid on Saturday night.
Casemiro re-joined Real Madrid last summer following one season with Porto and has developed into a key player for the Spanish giants over the last couple of months.
Marcelo has paid tribute to the qualities of his fellow Brazilian and claimed that the 24-year-old "has huge potential".
"For me, [Casemiro] is doing a great job. He's never protested when he hasn't played, and he's been given his opportunity to play for Madrid," Marcelo told reporters. "He's helping the team and a lad who has huge potential. He'll be doing much more than he is now. For us, it's very important to have a fit Casemiro."
Real Madrid will go in search of an 11th European Cup in Milan on Saturday night.