James tore his Achilles while training away from the team facility in early May.
Broncos players were among the NFL's first to opt out of voluntary offseason workouts due to COVID-19 concerns. The NFLPA has continued to advise players not to attend voluntary practices.
James was scheduled to make $10 million in base salary for the 2021 season. However, contracts aren't guaranteed for injuries suffered away from the team.
The veteran offensive lineman is strongly considering filing a grievance through the players association over his potentially lost wages, a source told Jeremy Fowler of ESPN.
James signed a four-year, $51-million deal with the Broncos in 2019, then a record for right tackles.
The 28-year-old called for the NFLPA to support him through this situation.