Long, who has been nursing a sore left knee all season, was absent when the Dolphins took the field for practice. The team's next game is Oct. 17 at Green Bay.
Long was listed on the injury report last week but didn't miss practice time and played the entire game Monday night against New England. Coach Tony Sparano declined to comment on Long's status.
Taking part in the workout was linebacker Channing Crowder, who has yet to play this season because of a groin injury.
Sitting out were defensive ends Jared Odrick (leg) and guard John Jerry (illness). Both attended the workout.
Defensive end Lionel Dotson was waived injured.