Richardson won the 2011 Doak Walker Award as the nation's best running back. He gained 1,679 yards this season, with 21 touchdowns. He picked up 96 yards and scored the only touchdown of the contest during Alabama's 21-0 win over LSU in the BCS National Championship game Monday.
He will be joined in the NFL draft this year by Alabama defensive back Dre Kirkpatrick and linebacker Dont'a Hightower. All three players had another year of eligibility with the Crimson Tide.
LSU will lose cornerback Morris Claiborne and defensive tackle Michael Brockers to the NFL. Both said Thursday they would bypass their final year of eligibility.
Claiborne had 51 tackles with six interceptions this season and led the nation with 173 interception-return yards. He won the Thorpe Award, which goes to the top defensive back in college football.
Brockers blocked a field goal attempt in the championship game.
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