The team announced Sunday that Shepard is back in the concussion protocol. The wideout passed tests and was cleared from the protocol on Friday after an appointment with an independent neurologist, but began to feel symptoms again over the weekend.
"He practiced fully this week and was limited with no contact the two weeks before that," Giants head coach Pat Shurmur said in a statement Sunday. "He told [Sr. VP Medical Services/Head Athletic Trainer] Ronnie [Barnes] last evening [Saturday] he didn't feel well and was sent for examination and evaluation. When he arrived for work this morning, he still did not feel well.
"At that point, the decision was made to continue in the concussion protocol."
Shepard missed the Giants' previous three games since sustaining his latest concussion in Week 5 against the Minnesota Vikings. The concussion suffered in the Vikings game was Shepard's second of the season.
Following the Giants' season-opener against the Dallas Cowboys, Shepard complained of concussion symptoms. He was then placed in the protocol and missed the team's next game versus the Buffalo Bills before returning against the Tampa Bay Buccaneers.
In four games this season, Shepard has 25 catches for 267 yards and one touchdown.