He's better than Odenigbo. Much better. I expect him to start and play heavy snaps.
Massive trunk helps him anchor. Long arms, heavy hands, explosively powerful. Fights across blocks which is a rare skill, has a punch or spin to disengage. Strong, powerful tackler - every tackle is a stop with no yards after contact. Has a knack for finding the ball in traffic and is alert to screens. Good playing temperament - often the first DL in his stance, very physical and pursues to the ball with motor.
It looked like UCLA's scheme asked their DTs to play off blocks and maintain their gap responsibilities. Diaz's defense could unlock his explosive power as he will be more aggressive getting upfield, shooting gaps.
He's actually very similar to Nesta so it will be interesting to see them both on the field at the same time as tone-setters.