It should have been one of his greatest moments as an Eagle. But LeSean McCoy will remember the day he became the franchise's all-time leading rusher in a much different way.

"I didn't play well at all," McCoy said. "It was probably one of my worst games . . . since being here."

McCoy fumbled on the first play of the second half, giving the Seahawks a short field to punch it in on their way to a 24-14 win Sunday at Lincoln Financial Field.

He wasn't in much of a celebrating mood later in the third quarter, when a 4-yard run pushed him past Wilbert Montgomery and into the Eagles record book. McCoy needed 48 yards to surpass Montgomery's total of 6,538. He ended up with 50 tough yards on 17 carries.

"I wish it could have been a different situation: us winning, me not having a terrible game," McCoy said. "It's obviously a great accomplishment, but it's hard to really enjoy it on a day like this."

McCoy more resembled the struggling back of the first five games than the one who averaged more than 6 yards per carry in his last three and who was second in the league in rushing since Week 6.

Darren Sproles didn't fare any better. He had four carries for no gain.

"I think it's a combination," Eagles coach Chip Kelly said of the struggles running the ball. "Sometimes it was there and we didn't hit it appropriately, and then other times, there were guys falling off their blocks. . . . We just have to sustain better up front."

The fumble, though, was McCoy's fault alone. He tried to jump cut out of the hole but held the ball too far from his body in his right hand. K.J. Wright knocked it loose and Seattle's Earl Thomas recovered on the 19-yard line.

Two plays later, Russell Wilson threw a 15-yard touchdown pass to Marshawn Lynch, and the Seahawks led, 17-7.

"It was terrible timing," McCoy said. "That's my fault. I should have been more aware of ball security and the situation of the game, trying to come back, and to get a turnover that fast, that's real bad."

Despite his propensity for swinging the ball wildly on runs, he has fumbled just 14 times in 87 career games. His four this year through 13 games equal the most he has had in a season.

"I'm not a fumbler," McCoy said. "I've had a lot of carries, and I don't really turn the ball over too much. I've got to get back to it, be more conscious of it, especially in traffic."

McCoy's struggles extended beyond running the ball. He missed a protection on the Eagles final drive, leading to a sack by defensive back Marcus Burley.

"I just didn't feel focused on some of the small stuff that I do well," McCoy said.

As McCoy left the locker room, he dropped a garbage bag and a brown leather backpack in the hallway. The championship belt he carried around after winning the rushing title last December would stay in storage for the day.

tmcmanus@philly.com

@ByTimMcManus