Valentine's exit from the program follows a suspension that prevented him from participating in spring practices.
In April, LSU coach Les Miles acknowledged that Valentine's future with the program was uncertain.
"We've instructed him to go to school, go to class, take care of your business,” Miles said after Valentine was suspended. “If he does that and handles behavior then there will be a future for him here. Otherwise, we're not certain.”
Over the last year, Valentine failed multiple drug tests and had a significant number of class absences, The Times-Picayune reports. He also reported late to the team because of academic problems.
Valentine's departure makes him the third player of LSU's highly touted 2014 draft class to leave the program this offseason. Former five-star linebacker recruit Clifton Garrett elected to transfer, and defensive tackle Trey Lealaimatafao was dismissed after being arrested on charges of battery and robbery in June.
Lealaimatafao and Garrett both transferred to Arizona Western Community College, and Valentine is rumored to be joining them.
Rivals.com ranked Valentine a four-star prospect out of high school. He was ranked the No. 3 defensive tackle and No. 59 overall prospect of the class of 2014.
- Erin Flynn