Giants wide receiver Sterling Shepard at MetLife Stadium on Aug....

Giants wide receiver Sterling Shepard at MetLife Stadium on Aug. 26, 2017. Credit: Daniel De Mato

The Giants don’t yet know what’s wrong with Sterling Shepard.

The wide receiver who complained of a migraine and missed Sunday’s game against the Chiefs seems unlikely to play against Washington on Thursday as the team attempts to determine the root of his discomfort.

“Sterling is not feeling well,” Ben McAdoo said after Tuesday’s practice in which Shepard did not participate. “They’re taking a look at him, they’re looking at all the possibilities.”

Shepard took several hard hits in the last game he played, against the 49ers on Nov. 12, but McAdoo said on Monday that Shepard was not in the concussion protocol. He was feeling well enough to be listed as limited in Monday’s brief practice, but regressed by Tuesday prompting the further examinations.

“They’re looking at it right now,” McAdoo said of the medical staff, “and they’ll let me know when they know.”

Greco ready

Veteran OL John Greco signed with the Giants last Tuesday. He may get his first start with the team on Thursday. With G D.J. Fluker likely unavailable because of a toe injury — he was in a protective boot on Tuesday — Greco could be asked to fill in against Washington.

“I’ll be ready to roll if need be,” Greco said. “I’m excited about it.”

Jon Halapio is another option for the Giants, but McAdoo said he has confidence in Greco despite his lack of familiarity with the team’s offense.

“He knows a lot of football,” McAdoo said. “He had to work hard to get familiar with our terminology, but he’s a bright young man and he’s picked it up fairly quickly.”

Giant steps

Washington has so many injured players that coach Jay Gruden said the team is unable to actually practice. “It’s quite the challenge,” Gruden said. “We’re only going to do walk-throughs this week. We’re pretty dinged up and we don’t have really enough guys to go 11-on-11 right now” . . . DT Damon Harrison (ankle) and DE Olivier Vernon (shoulder) were limited for the Giants after missing practice on Monday . . . OL Justin Pugh (back) said he hopes to return to action next week against the Raiders, but vowed not to rush back until he is 100 percent healed. He was encouraged by the play of rookie Chad Wheeler, his replacement at RT on Sunday. “We’ll see,” Pugh said, “maybe I’ll be able to go back to guard.”

More Giants

Newsday LogoSUBSCRIBEUnlimited Digital AccessOnly 25¢for 5 months
ACT NOWSALE ENDS SOON | CANCEL ANYTIME