His tender right knee reduced him to half the athlete he normally is. It rendered him useless as a sideline spiritual leader, keeping him tethered to the Washington Redskins’ bench between offensive series. But on a day when Robert Griffin III was forced to make concessions to his injury, he retained the identity that matters most to him professionally: quarterback of the Redskins.

It was still plenty good enough. Despite being limited physically by the lateral collateral ligament he sprained two weeks ago, Griffin relied on his arm to beat the Philadelphia Eagles, 27-20 — placing the Redskins, who host Dallas in the season finale next Sunday, one win from claiming their first NFC East title in 13 years.

Asked if he felt like himself Sunday, he replied tongue-in-cheek: “We won the game. I was playing quarterback for the Washington Redskins, so I felt like myself out there.”

For one game at least, Griffin was no longer the revolutionary offensive hybrid of weeks past, redefining the quarterback position with a combination of sprinter’s speed, arm strength and accuracy.

On Sunday, a bulky knee brace restricted his movement and took away his explosiveness outside the pocket, and the Redskins minimized his exposure to risk by shying away from designed runs for him. Normally, the Redskins use the pistol formation, with Griffin lined up about four yards behind the center, for the vast majority of their plays. But on Sunday, he was under center for half of the team’s 52 plays.

“We did not do everything we would normally do,” Coach Mike Shanahan conceded. “I did not want to put that pressure” on Griffin’s knee.

Still, if there were critics who postulated that Griffin would be unable to win without the threat of running, this was his personal rebuttal. Griffin has always bristled at the notion that he is less of a passer than his peers simply because he also has the ability to run, and on Sunday, operating as something of a straight drop-back passer, he still posted a 102.4 quarterback rating, with 198 yards, two touchdowns and an interception — his first in more than a month — that came on a tipped ball.

“He’s a guy who can throw with the best of them,” fullback Darrel Young said. “It was different for our game plan, but you have to be able to adjust in this game, and he showed he can do just that.”

Griffin’s knee injury, suffered on a scramble out of the pocket against the Baltimore Ravens on Dec. 9, forced him to sit out last week’s win at Clevelandagainst his wishes — and he wasn’t cleared to start Sunday against the Eagles until the day before.

In order to take the field Sunday, Griffin had to wear the brace — similar to one he had worn at Baylor in 2010, following knee surgery the previous year — and he sometimes appeared uncomfortable in it. In pregame warm-ups, he frequently tugged at the brace to adjust it.

Between offensive series, Griffin typically paces the Redskins’ sideline, encouraging teammates and staying close to the action on the field. But on Sunday, he stayed planted on the bench, holding what appeared to be an ice pack wrapped in a towel against his knee until it was time for the offense to take the field again.

“Any time you wear a brace it’s going to restrict your motion,” Griffin said. “My mobility was down a little bit. But at the same time, I was still able to do everything a quarterback is supposed to do. It didn’t necessarily slow me down by any means.”

Griffin may have been without all his tools on Sunday, but he seemed to take a perverse pleasure in winning despite those limitations. No longer can it be said that he can’t succeed if he can’t run.

“That’s why they call me the quarterback, [not merely] a running quarterback, or whatever else anyone wants to say,” Griffin said. “They call me quarterback because I lead the team.”