Boyd (knee) wasn't spotted on the field during the portion of Thursday's practice that was open to the media, Jay Morrison of The Athletic reports.
Boyd is thus in line to go down as a non-participant in practice for the second straight day, putting his status for Sunday's game in Cleveland on murky ground. The Bengals, who have already shut down two of their best pass catchers for the season in No. 1 receiver A.J. Green (foot) and top tight end Tyler Eifert (ankle), can hardly afford another significant absence at wideout, especially with the inexperienced Jeff Driskel under center. If Boyd is sidelined for Week 16, John Ross (knee) would likely rank as Driskel's top target, but the Washington product wouldn't make for a particularly comfortable lineup option.