"If you don't have that, the relationship isn't the same," McCoy said as the Eagles prepared to host the Cowboys Sunday. "I ain't perfect. You gotta have thick skin.
"He has that player mentality, that attitude where he's fired up. Sometimes he's talking to me like he's out there running. We talk. He challenges me to do different things. I like that. I like a [coach] that challenges some of his top players, where most coaches might let their guys go. Where there's a play, you've got to make it. If there's a block, you've got to pick it up. He'll let you know . . . He gives a different approach than other coaches, because he wants me to be great. At times he'll ask me, 'How great you wanna be?'
"We just talk all the time. It's never a negative thing. We never holler at each other. I like coach Kelly. I'm so glad he's here."
McCoy, 25, has good reason to like Kelly; not only does he lead the league in rushing yards, he leads it in carries, with 123, 20.5 per game. McCoy's career high is 273 carries (for a career-high 1,309 yards) in 2011. He's on a pace for 327 carries and 1,680 yards, though running backs coach Duce Staley vowed recently to keep McCoy under 300 carries, to prevent using him up prematurely.
McCoy was an Andy Reid loyalist. He had a lot of questions about Kelly when the new coach arrived, but Kelly's spread-the-field, run-heavy approach has been perfect for a back with McCoy's quickness and cutback ability.
Kelly said yesterday he'd watched McCoy highlights but didn't really know the player he was getting when he signed on to coach the Eagles in January.
"Did I know how talented he was? The one thing I've been really impressed with LeSean is that he's a complete running back," Kelly said. "I think you look at him in blitz pickup and some things that go a little bit unnoticed . . . a couple times, the Giants brought blitzes and just he stepped up and stoned the linebacker in the hole.
"His ability right now as a receiver coming out of the backfield - if people are going to play man coverage, somebody has to cover your running back and he's a guy that we can create some mismatches with, with some linebackers in this league.
"I didn't know as much about his ability as a blocker and some of those aspects. Obviously you saw the highlight runs and got a little sample size . . . but I think his ability to be a complete back is really what's impressed me, and his durability. He's been great so far, knock on wood."
McCoy got the Eagles going in Tampa by taking a screen 44 yards on the first play. He was asked yesterday what makes a back effective on screens.
"First of all, you've got to catch the ball, and two, just kind of set up your blocks," he said. "By the way, I should have scored" on that opening play, instead of being chased down.
McCoy said Brian Westbrook, an early mentor, texted him after the game and said, " 'Come on, bro. You're supposed to score on that play.' We talk still, all the time."
Center Jason Kelce was asked whether McCoy has improved or he's finally in an offense that is committed to giving him a central role, week in and week out.
"First of all, this is a great offense to run the ball in," Kelce said. "It does a great job of utilizing the entire length of the field, the width of the field. It makes a team spread out to cover that, which in turn gets you more running lanes. Obviously, the offensive-line health has been better than last year. I really think his approach has been really solid this year. It seems like he's really been focused - not that he hasn't been focused in years past, I don't want to say that at all - but he's maturing a bit, I guess would be the word."
Right guard Todd Herremans also used the word "maturing." The history of athletes and controversy teaches us to shy away from sweeping conclusions, but at least since training camp began, as far as we know, McCoy hasn't thrown any women off any party buses or engaged in any messy Twitter spats with the mother of his son. (These things did make the news in the previous months.)
Second-year back Bryce Brown said he sees McCoy as a leader and a mentor, the way McCoy saw Westbrook.
"He's a good example for all us young guys to model our game after," Brown said. "How he comes to work and prepares - he's a good leader. The time that we have [with him], I think all of us should take advantage of."
Left guard Evan Mathis said he thinks Kelly's offense spreads out defenses in that they have to focus on both the run and the pass, they can't shut down the Eagles (or McCoy) by choosing one aspect and going after it.
"It does create more lanes for a running back like LeSean, who is shifty and can find an open holes pretty well," Mathis said.
On Twitter: @LesBowen