Penn State safety Jaquan Brisker received second-team All-American honors, while punter Jordan Stout and wide receiver Jahan Dotson took home third-team recognition.
Parents of Shaka Toney and Micah Parsons got in on the jersey-swapping action while their sons battled on the gridiron.
In a statement, Roberson thanked his coaches for "taking a chance" on him and said he'll look for a new home with three years of eligibility remaining.
Diaz has led successful defenses at Texas, Middle Tennessee, and Miami.
Diaz has 24 years of collegiate coaching experience and was most recently Miami's head coach.
"I could not pass up the chance to be with this family and play the game I love again."