Bron­cos out­side line­backer Von Miller sus­tained an ankle injury dur­ing Tuesday’s prac­tice that will like­ly end his sea­son, accord­ing to a source.

The injury is believed to involve a ten­don, although not the Achilles, said the source, who described it as a “freak injury,” near the end of prac­tice. When asked if Miller was going to miss the sea­son, the source said it’s “look­ing that way.”

Because of poor weath­er con­di­tions, the Bron­cos prac­ticed inside for the first time since they opened train­ing camp and it was also the first work­out that wasn’t open to the media in its entire­ty. Miller was injured on one of the final plays of prac­tice and under­went an MRI Tues­day evening.

If Miller is out for the sea­son or for a sig­nif­i­cant part of the year, it’s a giant blow to the Bron­cos’ sea­son six days before they open against Ten­nessee. After post­ing only eight sacks last year, his fewest in a full sea­son, Miller spent the off­sea­son under­tak­ing an intense train­ing pro­gram that saw him add a few pounds and also improve his conditioning.

Out­side line­backer Bradley Chubb is return­ing from a left ACL injury sus­tained last Sep­tem­ber. He was pulled from prac­tice Aug. 29 and has not been a full par­tic­i­pant since. Even if he plays against the Titans, Chubb is expect­ed to have his play­ing time man­aged ear­ly in the season.

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Behind Miller and Chubb are Malik Reed and Jere­mi­ah Attaochu. Rook­ie Der­rek Tuzs­ka is on the prac­tice squad after clear­ing waivers Sun­day. The Bron­cos waived out­side line­backer Justin Hollins on Sat­ur­day and he was claimed by the Los Ange­les Rams.

Miller, 31, has missed only five reg­u­lar-sea­son games because of injury in his career — one game apiece in 2011 and ’19 and three games in ’13 when he tore his ACL. The Bron­cos’ all-time sack leader (106), Miller has been named first-team All Pro three times and to the Pro Bowl sev­en times.

If the injury is sea­son-end­ing, it’s con­ceiv­able Miller has played his final game with the Broncos.

The final year of Miller’s con­tact in 2021 car­ries a cap num­ber of $22.125 mil­lion, high­est on the team. If the Bron­cos cut him before June 1, 2021, they will cre­ate $13.875 mil­lion of cap space that could be allo­cat­ed to new con­tracts for Chubb or safe­ty Justin Simmons.

In the last week, two pass rush­ers have found new homes — Jack­sonville trad­ed Yan­nick Ngak­oue to Min­neso­ta and Jade­veon Clowney signed with Tennessee.

If the Bron­cos seek a vet­er­an pass rush­er, avail­able names include Clay Matthews, Cameron Wake, Ter­rell Sug­gs and Brooks Reed. Matthews, Wake and Sug­gs would bring sig­nif­i­cant pass-rush­ing pro­duc­tion to the Broncos.

Matthews, 34, played a decade for Green Bay (five Pro Bowls and 83 1/2 sacks) and spent last year with the Los Ange­les Rams (eight sacks).

Wake, 38, has 100 1/2 career sacks, but had only a com­bined 8 1/2 sacks the last two years for Mia­mi and Ten­nessee. Sug­gs, 37, has 139 career sacks for Bal­ti­more (16 years) and Arizona/Kansas City (last year). He had 11 sacks for the Ravens in 2017.