Smith was named the 2015 Butkus Award winner as the nation's top linebacker. He tore his ACL and MCL the 2016 Fiesta Bowl loss to Ohio State on Jan. 1 before undergoing reconstructive knee surgery last week.
Smith announced his decision in a Youtube video, which can be seen below:
Smith finished last season with 115 tackles for the Fighting Irish, which includes nine tackles for loss. As a sophomore, he recorded 112 tackles.
Fighting Irish head coach Brian Kelly did several interviews with ESPN on Monday and commented on Smith's decision.
“I think he's a generational player at his position, and he'll recover fine from this,” Kelly said. “The NFL will be lucky to get a young man like this.”
- Christopher Chavez