Peyton Hillis.JPG

Giants running back Peyton Hillis' season is over after suffering a concussion on Sunday in Seattle. (William Perlman | NJ Advance Media)

(William Perlman/The Star-Ledger)

Two Giants players suffered concussions on Sunday in Seattle. Neither are ready to play this week against the San Francisco 49ers, and both are believed to have played after obtaining the head injuries.

After running back Peyton Hillis was placed on season-ending injured reserve on Saturday, he told ESPN's Josina Anderson the concussion occurred during a first-quarter play when the back of his head slammed against the CenturyLink Field turf following a reception. It was Hillis' self-proclaimed third career concussion.

"It was a catch over the middle," he said. "Some guys team-tackled me and my head hit the back of the turf. It was just one of those deals."

That play occurred at 7:01 of the first quarter. Hillis later covered a kick (and was credited with a tackle) with 4:32 remaining in the first. He was declared out of the contest moments later with a concussion.

A Giants spokesman said Hillis self-reported his symptoms, was put through the concussion protocol and immediately removed from the game.

The Giants explained earlier in the week that linebacker Jacquian Williams likely played most of the final three quarters with a concussion. Williams' injury is believed to have occurred on a nondescript play early in the second quarter. He showed no symptoms and didn't develop headaches until the team returned from Seattle.

Hillis is a different story. His head clearly slammed against the turf when he was tackled. He adjusted his helmet as he walked off the field.

There is supposed to be a trainer watching for exactly these kind of things.

According to an NFL.com report in October 2013:

Hills, 28, remained in the game Sunday for one more play, the kickoff return several minutes later. It was the final play of his season and possibly his career.

Coach Tom Coughlin said Wednesday that Hillis and Williams were "not good" and sent home from the team's facility.

Jordan Raanan may be reached at jraanan@njadvancemedia.com. Follow him on Twitter @JordanRaanan. Find NJ.com Giants on Facebook.