Giants WR Sterling Shepard was on the field Thursday before practice officially got underway, stretching and casually tossing the football with his teammates before heading to the sidelines.
Shepard, who was wearing his helmet and pads, was in Pittsburgh on Wednesday to see a concussion specialist after his concussion symptoms returned over the weekend.
The receiver, who was a full practice participant at the end of last week, had been cleared and was expected to play Monday night against the Patriots before his symptoms returned and he alerted the team.
Giants head coach Pat Shurmur said on Tuesday that Shepard's concussion issues required a "serious response."
"This is a serious injury, and in my mind, it requires a serious response," Shurmur said. "I think we have to use good judgement and we need to be very deliberate about guys coming back from injuries such as this. At some point, we just have to use our gut."
SNY's Ralph Vacchiano reported on Wednesday that the team was considering placing Shepard on IR, but that any potential decision was likely a "long way" off.
Shepard, who suffered his first concussion of the season in Week 1 against the Cowboys and second concussion in Week 5 against the Vikings, told the team this past Saturday that he wasn't feeling well.
According to Shurmur, Shepard told the team late Saturday that he wasn't feeling good, and that was the same result on Sunday as well.
Through four games this season, Shepard has 267 yards and one touchdown on 25 receptions (34 targets). He signed an extension with the Giants before the season at $41 million over the next four seasons.
The Giants could be severely undermanned on Sunday against the Jets, with Shepard and tight end Evan Engram (foot) both expected to be out.