You could see it in the way he always bounced outside. You could see it in his eyes before he received a handoff from Nick Foles late in the third quarter with the Eagles down only four points.
With Bengals nose tackle Pat Sims bearing down on him, Brown took a peek before the exchange. He never had possession of the ball and it squirted out when contact was made. Cincinnati defensive end Wallace Gilberry scooped the ball up and ran 25 yards the other way for a touchdown.
"They got penetration as I was going downhill," Brown said. "He could have hit Nick. He could have hit me. But they did a good job of getting penetration and getting there before the exchange. . . . From what everybody's telling me, they said there's not much that I could have done."end
It got much worse, actually.
The Eagles turned the ball over on their next two plays. Repeat - their next two plays. Clay Harbor fumbled after a catch and Cedric Thornton muffed a short kickoff, and the Eagles lost, 34-13, to the Bengals. Their record fell to 4-10.
But Brown's fumble was the killer and it was the third time in four games that his turnover cost the Eagles the game.
He wasn't supposed to be in this position in his first full season since high school. LeSean McCoy's concussion forced the rookie into the starting lineup and he performed spectacularly in his first two starts - when he held onto the ball. Brown ran for 347 yards and four touchdowns in those games.
But he has managed just 40 yards on 28 carries (1.4 yards average) in his next two games. The Eagles faced two strong run defenses the last two weeks, and he wasn't aided by Marty Mornhinweg's lack of imaginative run-calling (another stretch play?), but Brown missed a number of holes that he should have cut back into.
"Where I run is kind of the play," Brown said. "I do what I do and see what I see. I try to make plays. We just got to make adjustments."
"We've got to do a better job of putting him in a better position," coach Andy Reid said. "I'll take that [blame] on the plays that were called."end
Brown's rare combination of speed (he has run a 4.3-second 40-yard dash) and size (6-foot, 223 pounds) had many salivating over the possibilities once McCoy was back and when the pair returned for next season.
If Foles or another young quarterback or perhaps an Alex Smith were under center, the Eagles could rely on a two-back system that played off the complementary Brown and McCoy.
But if Brown can't hold onto the ball, and even worse, if the fumbling has already gotten into his head, then there would be little reason to give him more than the five or so carries he received when McCoy was healthy.
Perhaps it's still a plausible idea. Much will depend on who AndyReid's replacement will be. If, say, San Francisco offensive coordinator Greg Roman were the guy and he brought his run-focused offense to the Eagles, maybe he could find a way to make it work.
Oregon's Chip Kelly would likely be enticed by Brown's talent. Coaches have been drawn to his blend of athleticism since he was a youth in Wichita, Kan. He was the top-ranked prospect coming out of high school and eventually ended up at Tennessee.
But he lasted only a season and transferred to Kansas State, where he lasted less than a season. He's obviously raw, but how long can the Eagles wait? They already have a franchise tailback who will be paid handsomely for the next several years.
Next offseason will be the most important of Brown's career, as it often is for players about to enter their sophomore seasons. He has a lot to work on - pass protection, catching the ball out of the backfield, and, of course, how he cradles the ball.
But if fumbling becomes a monster within, you can forget about a McCoy-Brown combo.
Contact Jeff McLane at firstname.lastname@example.org or on Twitter @Jeff_McLane.