Ruffin was injured in the Rebels' 76-72 win over No. 25 LSU on Tuesday night, when he scored 19 points in 20 minutes.
"Daeshun was just hitting his stride and was establishing himself as one of the best point guards in the SEC," Ole Miss coach Kermit Davis said. "I feel badly for Daeshun, but I know he will attack rehab with a great maturity and will return stronger than ever next season."
Ruffin missed eight games after breaking his right hand in the season opener. He was averaging 12.6 points, 3.4 assists and a team-high 2.3 steals per game.
Ruffin was the first McDonald's All-American to sign with the Rebels.