The NFL concussion protocol failed Sterling Shepard, so the Giants might have to use some old-fashioned instincts and common sense to protect their receiver from himself.

Shepard was cleared to return from his second concussion of the season by team doctors and an independent neurologist Friday, but reported a return of symptoms Saturday night. He is back in the five-step NFL concussion protocol, did not play Monday against the Cowboys and is prohibited from speaking to the media by rule.

“We have to use good judgment and we have to be very deliberate about guys coming back from injuries such as this,” coach Pat Shurmur said. “There’s signs and there are things that they go through the protocol, but there’s also the activity and how they respond to it. At some point, we have to use our gut.”

Shepard waved off assistance from the sideline during Week 1 and stayed in the game. Independent concussion-spotters somehow missed when he fell to the ground as teammates waved for attention after a helmet-to-helmet hit.

After missing two games, Shepard returned and suffered another concussion when a defender landed on top of him as they battled midair for a catch in Week 5. He finished that game, too, before reporting next-day symptoms.

“This is a serious injury, and in my mind it requires a serious response,” Shurmur said. “We want to make sure he’s well when he goes back out there.”

Shepard’s admitted eagerness to get back on the field makes taking his word for his health tricky for medical evaluators who are responsible for preventing just that kind of team-first warrior attitude.

“It’s scary getting two concussions, so I definitely will be honest on how I’m feeling and be honest with the trainers,” Shepard said last week. “It’s a tough deal with concussions. They don’t really know much about them and about the brain, so you have to give yourself time to recover and I understood that part of it. Was I happy about it? Probably not, but I understood it.”

How did he make it through the fifth step – full-contact practices – and gain clearance if he still had a concussion?

“I’m not a doctor so I can’t tell you that,” Shurmur said. “There’s also what I see and what he released to us about how he feels that we have to take into consideration.”

Shepard, 26, is a husband and father with a second child on the way with wife and Victoria’s Secret model Chanel Iman. He signed a four-year, $41 million contract extension in the offseason and has 25 catches for 267 yards and a touchdown in four games.

It is possible he could be shut down for the rest of the season.

“As a coach … you watch them practice and see how they respond to it and handle it the next day,” Shurmur said. “As we went through that process, he wasn’t feeling well, so we made a decision. I just think we have to be smart and very observant in these situations because player safety is on the front-burner for us.”

The only injury Shurmur noted from Monday’s game is a “sore foot” for tight end Evan Engram, who was held out late in the fourth quarter.

“I don’t have any details on that,” Shurmur said. “We’ll just have to see how the week goes on how he will do.”

Trailing 30-18 with less than six minutes remaining from their own 15-yard line, the Giants punted on fourth down and only gained one more offensive possession.

It’s the conventional move, but Shurmur gambled (and lost, via a turnover for downs) on a fourth-and-15 deep in his own territory against the Cardinals two weeks earlier. Why the less aggressive move?

“We had the timeouts there,” Shurmur said, “and felt like it was the right thing to do at that point.”

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