But can you fault him? Brown, 21, played only 13 games in college and is running behind an offensive line that, through injuries and ineffectiveness, has been a glaring weakness of the team. Against the Lions, stretch play after stretch play was blown up in the backfield, long before lanes could materialize.
With all of that, was there any reason to expect a young running back to succeed?
"For me, or any running back, it is just about getting a feel for the game," Brown said Monday. "The more carries I get, the better feel I get. I haven't been in there too much. Like last week, I only got five carries - but my thing is, I am just being patient and waiting my turn."
A former top high school recruit out of Wichita, Kan., Brown played his freshman season in 2009 at Tennessee, where he got 101 carries as Montario Hardesty's backup. He transfered to Kansas State and sat out a season. In 2011, he carried the ball only three times, then entered April's draft, where the Eagles took him in the seventh round.
When, in late August, the Eagles decided that instead of signing a veteran ballcarrier, they would back up their best player with inexperienced Brown, Dion Lewis and Chris Polk, it raised some eyebrows. When Brown emerged as the No. 2 back, it raised some more. Before training camp, he hadn't seen significant game action since 2009.
"It is really hard for me to think back and compare my college to now," Brown said. "I don't do too much thinking about my college career. I don't even remember too much about my freshman year, and I can't really comment on Kansas State, because I barely played there. So I guess I can just look back at preseason."
Brown was remarkable in preseason, running for 122 yards and a touchdown on 28 carries and drawing praise from scouts who again saw the guy who was once the No. 2-rated high school back in the country. But that success has yet to materialize in the regular season. Heading into a matchup with the 6-0 Falcons, there would be no better time for that to happen than now.
Atlanta gives up an average of 143.8 yards per game on the ground, 28th in the NFL. After losing tackle-machine Curtis Lofton to division rival New Orleans, the Falcons have been soft up the middle under new defensive coordinator Mike Nolan's nickel-heavy scheme.
Their 6-0 record is slightly deceiving, just as was the Eagles' at 2-0. The Falcons have won three games in the final minutes - against the lowly Panthers, Redskins and Raiders - after being gashed on the ground.
The Falcons' pass defense, on the other hand, is ranked 12th. They're second in the NFC in turnover differential, at plus-10 (the Eagles, at minus-9, are last). And the high-flying Atlanta offense averages a whopping 28.5 points per game. In short, all signs should point toward the run game for the Eagles.
Granted, should the Eagles surprise everyone and come out running, McCoy obviously will be doing the heavy lifting. But the five carries Brown got and the 18 snaps for which he was on the field against the Lions were a season high. While he has yet to bust a big run or even put together several good ones, the rookie hasn't lost his confidence.
"It is still pretty high," he said. "I am confident in myself and the players around me. And I am confident in my coaches. Some things are going to happen in the course of the season, and I think it is good for us. We're going to bounce back."
The biggest hurdle for Brown in training camp was learning to pick up the blitz, as is the case with many rookie running backs. The fact that he is playing shows he has done his homework.
"It comes down to trust," he said. "The more I can improve each week, the more I think I can show them I can play more as we go throughout the season.