Casemiro has been a key player for Real Madrid in each of the last three seasons, and made 42 appearances in all competitions last season as Los Blancos won a La Liga and Champions League double.
Silva, who won the 1994 World Cup as Brazil's holding midfielder, has lavished praise on his countryman, insisting that there is not a better defensive midfielder in the world.
"I love Casemiro, he's a soft spot of mine," he told Marca. "He does everything well. He places himself in front of [Madrid's] defence and gives calmness to the whole team.
"He always moves intelligently, distributes well – and has added goals to his repertoire! He always knows what his team need at all times. For me, he's the best in the world in his position."
Casemiro has won one La Liga, one Copa del Rey and three Champions League titles during his time at Real Madrid.