Jennings (concussion) wasn't spotted at Friday's practice, Mike Reiss of ESPN.com reports.
The Florida A&M product was unable to practice all week, so it's unlikely that he'll be able to suit up for Sunday's divisional matchup against the Bills. Both Craig Reynolds and D'Ernest Johnson are candidates to be elevated from the Patriots' practice squad to the active roster if Jennings is sidelined in Week 15 as expected.