The Post Sports Live crew dissect the Redskins performance in the loss to the Eagles on Monday night. (Post Sports Live/The Washington Post)

Robert Griffin III returned to FedEx Field and was greeted by a wave of adulation Monday evening, eight months after having his damaged right knee surgically repaired. But Griffin’s real-life fulfillment of his “All In for Week 1” vow veered off script.

The Washington Redskins quarterback threw two interceptions and, at least until it was too late, too rarely resembled the electrifying player who was last season’s NFL offensive rookie of the year. The Redskins fell behind by 26 points and couldn’t overcome their early stumbling and bumbling in a 33-27 season-opening defeat to the Philadelphia Eagles.

Throws sailed wide of receivers or landed in the arms of Eagles defenders as Griffin, for most of the night, looked exactly like what he was — a quarterback who missed all of his team’s offseason practices, participated in only portions of training camp and didn’t play in the preseason. He found little room to run when he scrambled out of the pocket. By the time he settled into something approaching a groove during the fourth quarter, in which he threw a pair of touchdown passes to wide receiver Leonard Hankerson, the outcome basically had been decided.

Griffin piled up some cosmetic passing numbers late and ended up connecting on 30 of 49 throws for a career-high 329 yards. He finished with 24 rushing yards on five carries. His uneven performance led former NFL quarterback Rich Gannon to write on Twitter during the third quarter: “Think veterans don’t need training camp? Check out RGIII, like a fish out of water. Doesn’t trust himself out there. Playing cautious!”

But Griffin did not attribute his play to a lack of preseason activity.

“I think that’s an excuse,” Griffin said. “I’m responsible for the way I play. I didn’t play very well in the first half. So that’s just the way it is. You move on from it. I’m not gonna sit here and say I was rusty. I’ve got to be accountable and I’m going to be accountable for that. I didn’t play well in the first half. We came back and played better in the second half. We’ve just got to do it for 60 minutes.”

Coach Mike Shanahan defended his approach of withholding Griffin from the entire preseason, saying he was glad to have Griffin healthy and in the lineup for the opener. He also said the Redskins’ problems on offense Monday were widespread.

“It’s everybody,” Shanahan said. “It’s just not one guy.”

Griffin was the final offensive player to be introduced to the crowd before the game, emerging from the inflatable Redskins helmet at the corner of the field at 7:04 p.m. Holding a Redskins flag in his hand, Griffin ran to the far end of the field and kneeled in the end zone. He joined the Redskins’ other team captains at midfield for the coin toss.

But with the Eagles using the fast-break offense of their new coach, Chip Kelly, to dominate possession of the ball in the game’s early stages, Griffin didn’t take the field for his first offensive snap until close to six minutes into the game.

He was greeted by the familiar “RG-3! RG-3!” chants from the crowd. He was at the same end of the field where his 2012 season ended late in the Redskins’ playoff loss Jan. 6 to the Seattle Seahawks, with Griffin crumpling to the turf as he was unable to reach a low snap due to his injured right knee. He underwent surgery three days later to have tears of his anterior cruciate and lateral collateral ligaments repaired, and his efforts to return to the lineup for this game became the focal point of the Redskins’ offseason, training camp and the preseason.

The rust on his game was evident from the outset, and others around him on the Redskins’ offense struggled along with him. The Eagles’ 26-7 lead at halftime could have been even larger if not for a couple of Philadelphia gaffes.

“We didn’t play well in the first half at all, had a serious case of the ‘can’t get rights,’ just penalties, hurting ourselves,” Griffin said. “I don’t throw picks. Alfred [Morris] doesn’t fumble and Kai [Forbath] doesn’t miss field goals, and all three of those happened tonight. We’ll get better, no doubt.”

Left tackle Trent Williams said he thought Griffin’s preparations in practices were enough to get him ready to play.

“You guys put him on a pretty big pedestal,” Williams said. “So anything he does wrong is gonna seem like a letdown. But I don’t feel like he played that bad a game. We still had a chance to win at the end and we just couldn’t pull it together as a team.”