Colts safety Julian Blackmon suffered a torn Achilles during practice on Wednesday and was placed on injured reserve.
Indianapolis has put 20 players on IR this season, including those designated to return.
The 2020 third-round pick stepped into a starting role when Malik Hooker injured his Achilles last season.
Until the injury report listed Blackmon on Wednesday as a limited participant, there was no previous sign of the injury.
Injuries have hit the Colts hard since training camp when guard Quenton Nelson, quarterback Carson Wentz, wide receiver T.Y. Hilton and cornerback Xavier Rhodes all had limited availability.
Blackmon’s injury leaves the Colts with just three safeties on the roster: Andrew Sendejo, Khari Willis and George Odum.
Blackmon has 34 tackles (two for loss), one pass defended and one forced fumble in six games in 2021.
–Field Level Media