FOXBORO, Mass — A Gronkowski was on the New England Patriots practice field Wednesday, but it wasn’t star tight end Rob.

Rob Gronkowski wasn’t spotted during the portion of practice open to the media Wednesday. His brother, fullback Glenn Gronkowski, was on the field after rejoining the practice squad.

Gronkowski has an undisclosed chest or lung injury suffered on a hit from Seattle Seahawks safety Earl Thomas in the Patriots’ Week 10 loss. Reports vary on the severity of Gronkowski’s injury, but he seems likely to sit out the Patriots’ Week 11 matchup with the San Francisco 49ers.

Gronkowski was the lone absence at practice. Guard Tre’ Jackson, who is on the physically unable to perform list, has yet to begin practicing with the Patriots.

Thumbnail photo via Scott R. Galvin/USA TODAY Sports Images