It's happened twice now. Twice in three games.
Ryan Mathews hasn't just fumbled, he's fumbled in the final five minutes of the fourth quarter twice in three games the Eagles were trying to put away.
The first one, with 2:41 left in Detroit, almost certainly cost the Eagles a win. The second one, with 4:46 left against the Vikings on Sunday, didn't cost them a win but it did cost a touchdown.
Complete coverage of the Philadelphia Eagles and their NFL rivals from NBC Sports Philadelphia.
Mathews is the only running back in the NFL to lose two fumbles in the last five minutes of a game this year.
In fact, the only other running back to fumble in the final five minutes of a game even once this year, according to the Pro-Football Reference play finder, is Jonathan Williams of the Bills, who fumbled with 4:37 left in the Bills' 45-16 win over the 49ers earlier this month.
So Mathews has fumbled in the final five minutes of games more than every other running back in the NFL combined.
He's also the first Eagles running back in at least 25 years to lose two fumbles in a season in late-game situations.
And he's the first NFL running back to fumble twice in the final five minutes of two different games in the same season since Ahmad Bradshaw of the Giants in 2010.
This is an issue.
"Well, it's definitely a concern, something we don't want to see, especially in four-minute situations at the end of the game," head coach Doug Pederson said Monday, after the Eagles improved to 4-2 with a 21-10 win over the Vikings at the Linc.
"We've got to continue to either find out if he's tired, where he's at at the end of the game, if we need to put Wendell (Smallwood) in there, put Darren (Sproles) in there, we'll find out about that."
But it's hard to imagine being tired is the cause of the fumbles.
The fumble in Detroit came on Mathews' ninth carry, and the fumble Sunday against the Vikings came on his 14th carry.
Mathews did run the ball effectively in Detroit and Washington, combining for 116 yards on 23 carries for 5.0 yards a pop. This is the first time he's been over 4.0 yards per carry in consecutive games since the seventh and eighth games of last year.
But Pederson is concerned enough about Mathews' fumbling to consider changing the late-game running back rotation.
"At no means am I down on Ryan at all," Pederson said. "We just have to make sure that he understands that he can't obviously do that and put ourselves in the situation where we're giving the ball back to our opponent."
Both fumbles came in situations where the Eagles were simply trying to run out the clock. Both led to scores.
In fact, the Eagles' defense has allowed only five second-half scores this year — four field goals, one touchdown — and two of the five were set up by Mathews fumbles.
Those fumbles led to more than half of the second-half points the Eagles' defense has allowed this year (10 of 19).
"It's an instinctive thing for a runner obviously to get as many yards as you can," Pederson said. "In that situation (Sunday), he was also fighting to get down, it was four minutes, trying to protect the sideline, stay in bounds, all that, and the secondary defender came in and punched the ball out.
"You just have to be cognizant of all that. That's what defenses are instructed to do, and we have to hang onto the ball to be able to finish the game."