LSU's Tyrann Mathieu is only the latest SEC star to be kicked off his team or leave abruptly.
Here's a look at three recent high-profile departures and how they affected, or could affect, the teams involved:
Georgia RB Isaiah Crowell: Coach Mark Richt dismissed the SEC's Freshman of the Year in late June following his arrest on three weapons charges. It was the latest in a series of off-field incidents involving Crowell. But despite missing time due to suspensions and injuries, Crowell ran for 850 yards and five touchdowns.
The Bulldogs are confident they can replace Crowell, who arrived as the nation's top-rated running back prospect. True freshmen Keith Marshall and Todd Gurley were rated nearly as highly as Crowell, and they join a backfield that includes sophomore Ken Malcome and senior Richard Samuel. Gurley shined in Wednesday's scrimmage, running for 58 yards and a touchdown on six carries.
Georgia enters the season ranked No. 6 by CBSSports.com.
Auburn RB Michael Dyer: The first Tigers tailback to run for more than 1,000 years in each of his first two seasons, Dyer transferred to Arkansas State in January after being suspended indefinitely for violating team rules before the Chick-fil-A Bowl. He was then dismissed in late July from Arkansas State, coached by former Auburn offensive coordinator Gus Malzahn. That dismissal came after a traffic stop in which Dyer allegedly was found with marijuana and a gun.
The speedy Onterio McCalebb should get the most carries in a committee that includes Tre Mason, Corey Grant and Florida transfer Mike Blakely. McCalebb ranks 15th in school history with 2,016 rushing yards and sixth in catches by a running back with 45.
South Carolina QB Stephen Garcia: Coach Steve Spurrier dismissed Garcia last October after he tested positive for marijuana and alcohol. The troubled quarterback had previously been suspended five times, and was let go for failing to live up to the terms of his reinstatement. Garcia had thrown for 3,059 yards and 20 TDs in 2010, but the Gamecocks didn't miss a beat with Connor Shaw.
He stepped in and led South Carolina to a 7-1 finish last year. With All-SEC RB Marcus Lattimore returning from a knee injury to take pressure off Shaw, the Gamecocks enter this season ranked No. 8 by CBSSports.com.
For more up-to-the-minute news and analysis from SEC bloggers Daniel Lewis and Larry Hartstein, follow @CBSSportsSEC.