FOXBOROUGH, Mass. -- New England Patriots starting right tackle Sebastian Vollmer was not spotted at the start of the team’s practice Wednesday, as he missed his third practice in a row for an undisclosed reason.

Vollmer’s situation bears monitoring as he has not been seen on the practice field since playing 22 snaps in Friday’s preseason win against the Eagles. His injury history is well-documented, which includes a broken ankle that landed him on injured reserve in the eighth week of the 2013 season

In other injury news, defensive tackle Sealver Siliga has progressed to the point that he is doing rehabilitation work with other players coming back from injuries. He was wearing a black protective cast/brace on his left hand Wednesday as he passed by reporters en route to practice. Siliga's presence indicates that his injury, sustained Aug. 5 in a joint practice with Washington, is probably not of a season-ending nature.

The following injured players weren't spotted at practice Wednesday: tight end D.J. Williams (right lower leg, Aug. 5), defensive tackle Chris Jones (left ankle, Aug. 7) and offensive tackle Chris Martin (non-football injury list).

The Patriots were practicing in shells and shorts.