McCourty left Sunday's game after tackling Ravens tight end Ed Dickson in the third quarter and did not return. The team officially announced it as a head injury, although it is unclear if McCourty suffered a concussion. Rookie safety Duron Harmon filled in for McCourty.
Boyce, meanwhile, suffered a Week 15 ankle injury against the Dolphins that kept him off the practice field all of last week and out of Sunday's game. The timetable for his return is unclear.
Running back Shane Vereen, who left Sunday's game with a groin injury, was on the field and taking part in team stretching. Safety Steve Gregory, who left the game Sunday with an undisclosed injury but did return, was present for the walkthrough but spent the media-access portion of it on the sidelines.