The Eagles were trailing by two touchdowns when Barkley came in, and he had no choice but to throw the football down the field out of desperation. Those are mitigating factors, but they only cover up so much. There was nothing comforting about watching Barkley struggle as he did. His performance even inspired pity from some of his teammates.
"It seems the offense isn't going well at all, and you're going to throw a kid who's only been in the NFL for, what, two months now in live situations," center Jason Kelce said. "I felt a little bit bad for him."
The sympathy will last only so long, of course, since the safe bet is that Barkley will start next week against the Giants. Michael Vick wasn't active Sunday, his hamstring still too tender for him to suit up. And it won't be surprising to hear the Eagles announce Monday that Foles suffered a concussion when the Cowboys' Jarius Wynn and George Selvie threw him to the turf on the third quarter's final play.
That Vick-or-Foles debate seems so quaint now, because instead of leading the NFC East, the Eagles are 3-4, essentially two games (one in the standings and one in the head-to-head tiebreaker) behind Dallas.
No, this can't be comforting at all for the Eagles, and for Barkley, Sunday was one more humbling episode in the most difficult year of his football life.
Had he decided to forgo his senior season at Southern Cal, he might have been the No. 1 overall pick in the 2012 draft. He stayed. Southern Cal went 7-6, scouts and talent evaluators questioned his arm strength, and Barkley's stock fell so far that the Eagles traded up to get him in the fourth round of this year's draft. The decision cost him millions of dollars and turned him into a cautionary tale, and nothing he did Sunday - the 11 completions in 20 attempts, the 129 passing yards, the way he locked his eyes on his receivers - dispelled those doubts.
After all that had gone wrong for him lately, Barkley had to be questioning himself a bit, didn't he?
"I don't think you can look at it like that and make excuses for yourself," he said. "This is a chance, and in this league, all it takes is one play. It took one play for Nick to get in, and it took one play for me to get in. You have to be ready, and you can't justify poor play with, 'Oh, it was a tough situation.' I'm not looking at it like that.
"More than anything, I think this is just a start."
His self-confidence was admirable. But if there had been any curiosity about whether the Eagles might have stolen themselves a starting quarterback when they selected him, he tempered it Sunday. He tempered it and then some.
After the game ended, Barkley found himself at midfield, talking with Cowboys quarterback Tony Romo. In his first NFL start, a loss to the Giants in 2006, Romo had thrown three interceptions, and he counseled Barkley not to let what happened Sunday stay with him. To his credit, Barkley didn't appear inclined to do so, anyway.
"I'll take this game in stride and learn from it and grow," he said, "but this game is not going to set a tempo for the rest of my career."
By then, people had started to peel away from Barkley's locker. He had said all the right things, and had handled a hard day by looking everyone in the eye and taking responsibility for his mistakes and focusing on the future. In those moments Sunday, Matt Barkley had looked like a starting quarterback - but only in those moments, and now he was standing alone again, amid the questions that always linger in the quiet of a losing locker room.