The 25-year-old has been linked with a shock return to Spanish football with Madrid, just three months after quitting Camp Nou to join Paris Saint-Germain in a record-breaking £198m deal.
Neymar is said to have fallen out with manager Unai Emery and a number of his teammates, leading to suggestions that Los Blancos - potentially in the market for a Cristiano Ronaldo replacement - could turn to the superstar forward.
Casemiro would be more than happy to see his compatriot make the switch next summer, telling COPE: "He's a star. He knows what he's doing. He's a great player and he'll always be welcome at Real Madrid. I hope he comes, but he's happy at his club."