PHILADELPHIA -- Eagles rookie running back Miles Sanders didn't want to curse in front of the media, he said, but he had to in order to explain what coach Duce Staley put him through after he lost two fumbles during a Week 3 loss to the Detroit Lions.

"It's called 'The Bitch,'" Sanders quietly told ESPN at his locker stall in September.

It's a wooden sled that's brought out for such an occasion. The offending player -- in this case Sanders -- has to push the sled from a bear-crawl position 150 yards for each fumble. Fifty yards up, then back, then up again. Sanders had to do it twice.

Only five @NFL players have recorded 600+ scrimmage yards and 4+ TDs since Week 11:

𝗠𝗶𝗹𝗲𝘀 𝗦𝗮𝗻𝗱𝗲𝗿𝘀 (𝗣𝗵𝗶.)
Saquon Barkley (NYG)
Ezekiel Elliott (Dal.)
Christian McCaffrey (Car.)
Michael Thomas (NO)#FlyEaglesFly pic.twitter.com/cb99FyLv0M

— John Gonoude (@john_gonoude) December 26, 2019

"He let me do them different days," said Sanders. "It's not fun."

But it is effective, apparently. Sanders, who had issues with fumbling at Penn State, has not let another ball hit the turf since.

That's the story of Sanders' rookie campaign in a nutshell: a bump in the road followed by a quick correction and from there, pure acceleration.

He enters Sunday's 2019 regular-season finale at the New York Giants (4:25 p.m. ET, Fox) ranked seventh in all-purpose yards (1,590), trailing Carolina's Christian McCaffrey, Cleveland's Nick Chubb, New Orleans' Michael Thomas, Jacksonville's Leonard Fournette, Minnesota's Dalvin Cook and Dallas' Ezekiel Elliott. Sanders is now the Eagles' all-time leader in rookie all-purpose yards following two standout performances against the Washington Redskins and Dallas Cowboys in which he racked up 278 yards and three scores.

"The kid's a baller," quarterback Carson Wentz said, "and we've got to keep finding ways to get it in his hand."

Giants running back Saquon Barkley has long known that fact. He said Sanders' ability was evident "when he first touched campus" at Penn State in 2016. Barkley was so aware of his understudy's talents that it pushed him to play through pain, including against Nebraska his junior year.

"That whole week I was hurt with a back injury," Barkley said. "I remember telling people, 'I can't not play because if I don't play, the world is going to see what this guy can do already, and it's not my time yet to leave.' So I kind of, didn't force myself, but that was in the back of my mind, to get back early so you can finish the season off strong and let him go do his thing next year."

Sanders had a chance to take center stage in 2018 for the Nittany Lions, rushing for 1,274 yards and nine touchdowns en route to becoming a second-round pick by the Eagles this past April.

He was given ample opportunity to secure the lead-back role early this season, but Jordan Howard took over that position instead, as Sanders had a tendency to bounce many of his runs outside. Sanders averaged 31 rushing yards per game over the first seven weeks. He found his footing on a wet field at Buffalo in Week 8 (3 carries, 74 yards, TD), and he was off to the races.

"The way he runs, he's very disciplined now with his eyes," center Jason Kelce said. "To watch his progression throughout the season has been a lot of fun."

The biggest surprise is how quickly Sanders has developed into a receiving threat. He was asked to do very little of that at Penn State -- he had 32 catches over three seasons -- and while there was belief he had the skill set, it was unknown how effective he could be catching out the backfield. That skill has turned into one of his greatest strengths. Sanders has 47 catches on 58 targets and ranks third on the Eagles in receiving yards with 510. He credits mentorship from Eagles running back Darren Sproles, extra work after practice with Wentz and on the Jugs machine and studying other backs such as McCaffrey and Alvin Kamara for his rapid development as a receiver.

"He's constantly wanting to get better and wanting to learn the detail part of route running," Eagles coach Doug Pederson said. "He's done a great job just paying attention to those little things, just like he is as a runner. He's made himself into an explosive back because of that."

With injuries hitting the Eagles' skill positions hard, Sanders has stepped up in a huge way, accounting for 40% of the team's total offense over the past two weeks. He is a late-charging candidate into the NFL Rookie of Year conversation. And, with 12 plays of 20-plus yards this season (fourth among running backs), he is suddenly one of the most dangerous offensive players in football now that he has left the learning curve in the dust.

"I think the biggest thing, man, is s---, he wanted to learn. He was hungry for it," said guard Brandon Brooks. "You could see it from Day 1. You got young guys who come in sometimes, high picks, who think they know it all. That wasn't the case for him, man. He came in humble, hungry, and I think the hard work is really starting to show and pay off."