He told reporters afterward he was fine, but an MRI on Friday revealed the diagnosis.
Instead, Guice's National Football League career starts with a medical redshirt. He had suffered a hyperextended knee (yes, the same knee) at LSU but opted against surgery, also per Rapoport.
"God never makes mistakes", Guice tweeted.
On Guice's sixth carry of the night, he was tackled from behind and stayed on the ground. Guice had appeared to be the front runner to start after an excellent performance in training camp.More news: Wake Forest assistant basketball coach charged with assaulting tourist
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Washington has a lot of imperfect running backs, and only Guice was a potential three-down player.
In a statement, the Redskins said Guice was expected to make a full recovery and looked forward to playing in 2019.
Injuries are one of the worst parts of sports. Washington had 23 players on injured reserve. Last season, Brady finished in the top five of all those categories during an MVP campaign.
Daron Payne, the team's 2018 first round pick, is nursing a high-ankle sprain, which caused him to be out 2-3 weeks.
Tom Brady, Quarterback, New England Patriots, and Founder of TB12, speaks at the Milken Institute 21st Global Conference in Beverly Hills, California, U.S., April 30, 2018. Tight end Manasseh Garner also suffered a torn ACL.