Former Porto coach Julen Lopetegui is delighted for Casemiro over his form with Real Madrid.
The pair worked together at Porto last season.
"He's got a clear idea of what he brings to the table and his mission on the pitch. He was decisive for us at Porto," explained Lopetegui to Marca.
"He's always on hand to provide balance. For an attack-minded team like we were and Real Madrid are, that makes him a key figure. He's always well positioned, constantly covering and offering an outlet.
"What's more, his physical prowess means he wins every 50-50, and he makes intelligent use of the ball."