Jontay Porter will miss the entire upcoming season after tearing his ACL and MCL on Sunday.
Porter suffered the injuries during a scrimmage on Sunday against Southern Illinois.
Porter was expected to be a mid-first round pick in 2019. Porter tested the draft waters last spring.
Knee problems have been an issue for the Porter siblings in recent years. Bri Porter, Jontay and Michael's sister, retired from basketball before last season at Missouri after suffering her fifth ACL tear.