The Philadelphia Eagles played their first game without future Hall of Fame center Jason Kelce last Friday, beating the Green Bay Packers 34-29 in São Paulo, Brazil. But he couldn’t stay away.

When Philadelphia, still leading by two points, reached the Packers’ 1-yard line with 1:12 left, Kelce sent out a tweet.

“Tush, push it stop!!!!!” he wrote on X.

Kelce, who now works as an ESPN analyst on “Monday Night Countdown,” had the right call. But the game didn’t go as it normally does for the Eagles. The exchange between new center Cam Jurgens and quarterback Jalen Hurts wasn’t clean. The ball hit the ground and an alert Saquon Barkley jumped on the fumble to prevent a near turnover.

Kelce’s next stop was Homer Simpson who backed into the bushes and disappeared from view.

The “Brotherly Shove” had only modest success in Week 1. There were four attempts in total. Two failed, one was successfully converted, and the other led to an encroachment penalty on Green Bay, resulting in an Eagles first down.

So it’s 50-50, which is below the high standards the team has set for this play. The Eagles have an 86% success rate (61 of 71) since they started playing it in 2022 — well above the league average of 76%.

“There’s no stopping it,” quarterback Will Grier said. “I’ve seen them do it for two years now.”

Yes, that was it.

The success rate has dropped off a bit lately. The Eagles got a first down on 93% of their tush push attempts in 2022 (25 of 27). In 2023, they used the play more, converting on an 83% rate (35 of 42).

Defenses seem to be getting better at slowing down the game, and now one of the greatest centers of all time is no longer in the thick of the action for Philly.

One week is a tiny sample, but the results heighten curiosity about one of the most talked about and debated plays in the NFL: What’s the secret sauce behind the tush push? And was Kelce the key ingredient all along?

THE TUSH PUSH is a simple play on its face. It’s glorified QB scrum, the only difference being that there are players lined up behind the quarterback — normally a running back and tight end — who provide an extra shot of momentum by pushing the quarterback forward into, and ideally through, the scrum.

The Eagles have one of the deepest offensive lines in football, with tackles Lane Johnson (6-foot-6, 325 pounds) and Jordan Mailata (6-8, 365 pounds) and left guard Landon Dickerson (6-6, 332 pounds) in the trenches. Add a former powerlifter in Hurts, who can squat more than 500 pounds, and now running back Saquon Barkley, who can lift around 600 pounds, and you have the makings of a potent short-yardage operation.

“It definitely helps how strong Jalen is and how strong I am and (tight end) Dallas (Goedert). It’s a great play,” Barkley said. “That play is going to be talked about for a long time and it’s tough to stop, so we plan on continuing to make it tough to stop.”

But the scientific equation involves more than just raw power, and that’s where Kelce came in.

“Kelce did such a good job of staying down low consistently,” Johnson said. “I think that’s why we’ve been so successful — him and our two guards and tackles kind of seeping in and making sure there’s no leakage. He did a good job with his leverage and really knew how to execute. We’re going to try to keep it at the same standard as far as execution, but as you know every (Eagles) team looks different, players look different, so we’re still waiting.”

The other key element, players say, is will. Head-to-head diving into a wall of humanity and being the lowest man in a pile of 300-plus-pound athletes isn’t for the faint of heart. The same iron-man spirit that helped Kelce set the franchise record for consecutive starts (156) allowed him to serve as the lead blocker for the play time and time again.

“Grit, man. Every time we did it, he was always like, ‘Man, we gotta do it? Okay.’ But when he did it, it was balls to the wall, 100 percent,” Mailata said. “We were gonna get that first down.”

According to ESPN Analytics/NFL Next Gen Stats, Kelce had a 91% run block win rate on push QB sneak plays last season, 16 percentage points higher than his overall run block win rate in 2023 (75%).

The Eagles’ overwhelming success in executing the tush push thrust the play into the spotlight and sparked debate over whether it belonged in the NFL.

Jack Del Rio, former defensive coordinator for the Washington Commanders, said he would like to see it go away before the Commanders and Eagles played each other last season. He called it “a fun game of rugby” but “not what we’re looking for in football.”

The NFL Competition Committee was “split” on whether to ban the game last offseason, according to Atlanta Falcons president Rich McKay, the committee’s chairman. The NFL ultimately decided in March that the game would remain legal through 2024.

“The league is still a fan of the game, which is shocking to some,” referee Brad Allen said before the season began. “But the one thing (the NFL) will tell us is that in that formation, when those running backs are that close together, they want to make sure that there’s some space between those running backs and the line of scrimmage. You can’t put them all the way in the gap because that creates an illegal formation. That’s about it. Other than that, they’re good at the game, they’re good at it.”

Beyond size, strength and leverage, repetition has served the Eagles well. Their 71 tush push attempts since 2022 are 41 more than the closest team (Bills, 30).

“Obviously Kelce is a special player and Jalen is a strong guy, and that’s not a bad thing, but compared to other teams I’ve played on, they just know here, it’s fourth-and-1, third-and-1, they just go for it,” Grier said.

THE LESS-THAN– Kelce believes Friday’s great start should be taken with a grain of salt.

“I don’t know if I’m the determining factor in the success of this,” Kelce said on his “New Heights” podcast, noting that the play was stopped during the team’s playoff loss to the Tampa Bay Bucs in January. “First of all, it’s a really tough play to make when a lot of guys are new to it. Once you’ve made it a couple times, you know how to play the quarterback sneak, you get into a rhythm and you understand how it’s going to happen.

“And I think they had a new piece at center with Cam… and then obviously Mekhi Becton was new at the right guard position.”

The same goes for offensive coordinator Kellen Moore: “Given the circumstances of that game, I think we had some great opportunities with the QB sneak element and we need to keep that as part of the whole.

“It’s a very important piece for us. … It’s a masterpiece and we feel very comfortable with it.”

Jurgens, a 2022 second-round pick out of Nebraska, was a favorite of Kelce’s coming out of that draft and has been coached to be his successor. Given his two years in the film room with Kelce and working with him as the starting right guard last season, Jurgens feels prepared.

“That’s the highlight of the wedge, so of course you have to make sure you have the right cadence and you start the snap right. That all starts with the center and the quarterback,” Jurgens said.

The pitch at Arena Corinthians in Sao Paulo was slippery, causing problems for players on both sides. Moore said “there was an element of slipping” in the late attempt on the goal line that resulted in a fumble. Had the conditions been different, the success rate might have been the same.

“You can only reproduce that snap and the way it feels live,” Kelce said. “And the reality is you’re leaning so far forward to get leverage that it’s a very difficult snap to get to the quarterback if you do it right. I think there were factors, especially with the slick field, that led to that fumble.

“I think the reality is that the more reps these guys get, the more it’s going to get back to that 90-plus percent success rate. That hasn’t discouraged me.”