A person with knowledge of the injury tells The Associated Press that Colts linebacker Robert Mathis is expected to miss the entire season after tearing an Achilles tendon during a private workout last week in Atlanta.
The person spoke Monday on condition of anonymity because the team had not confirmed Mathis' injury.
Mathis began a four-game suspension on Aug. 30. He has penalized for violating the league's performance-enhancing substance policy and was expected to return to the team following the Colts' game Sept. 28 against Tennessee.
Mathis led the NFL with 19.5 sacks last season and was expected to give Indy (0-1) a pass-rushing boost.
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