EAST RUTHERFORD, N.J. -- It began on Oct. 17, 2015. That was the day when Penn State freshman running back Saquon Barkley introduced himself to the football world with a 194-yard rushing effort against No. 1 Ohio State at the famed Horseshoe. It was also the beginning of an unexpected friendship.

Barkley was approached after that game near midfield by Ezekiel Elliott, then Ohio State’s star junior running back, who remembers leaping over a defender on one drive and watching Barkley do the same thing on the very next drive. Elliott had some complimentary words for Barkley on the gridiron and later when speaking to the media.

“A real big shoutout to that freshman running back,” Elliott told reporters after the game. “He’s definitely the truth.”

Barkley noticed. It meant something to him that Elliott would heap such praise on a freshman who was playing in his fifth career game.

This was Ezekiel Elliott, the top running back in college football and eventually the No. 4 overall pick in the next NFL draft. Barkley admitted later he was giddy just to be on the field that day with Elliott and Buckeyes quarterback Braxton Miller. That he opened Elliott’s eyes was a bonus.

That sparked a friendship that has encouraged the two running backs to remain in touch ever since. Their second career matchup will be Sunday night when Elliott and the Dallas Cowboys host Barkley and the New York Giants at AT&T Stadium.

"When I look at Zeke, something I want to get better at that he does is downhill running, understanding situations and taking what the defense gives you. Just lowering your shoulder and doing that."

Saquon Barkley

“We kind of kept in contact after that game,” Barkley said of that 38-10 Ohio State victory in 2015.

They’ve texted and spoken. Barkley even told Newsday that Elliott sent him a congratulatory text after he rushed for 106 yards and had a 68-yard touchdown run in his NFL debut.

"Just hitting him here and there, giving him a little bit of motivation, seeing how he’s doing," Elliott said.

Elliott and Barkley were supposed to meet up and train together in Los Angeles this offseason, but their schedules didn’t align. Barkley had to leave just days before Elliott arrived. It was disappointing.

Barkley, the No. 2 overall pick by the Giants this year, studies almost all the top running backs. He watches film of Todd Gurley II (whom he did work out with in Los Angeles), Elliott and Le'Veon Bell, among others. Barkley wanted to pick Elliott’s brain, and he still plans to do so sometime in the future.

Barkley and Elliott, on the surface, are unexpected friends. Barkley is reserved and soft-spoken, conscious of his image and careful with his words. Elliott is more boisterous, an emotional roller coaster with a fair share of off-the-field incidents on his résumé.

But there are similarities: easy smiles, engaging personalities and rare skills.

They can do it all. Giants coach Pat Shurmur raved at what he called their "collision balance." They both possess that unusual trait, which allows them to excel as runners and blockers.

But they mostly go about their business in different manners. Elliott is a home run hitter who thrives running in the middle of the field and loves lowering his shoulder into the chest of defenders. Barkley is a big play waiting to happen who runs pristine routes but prefers to bounce his runs outside.

“Man, I definitely think Saquon is a different runner,” said cornerback Eli Apple, a former teammate of Elliott at Ohio State and now teamed with Barkley on the Giants. “Saquon has some crazy shiftiness. Zeke does too, but they move differently.”

There is something for Barkley to learn from watching Elliott’s tape and picking his brain. Elliott didn’t rush for an NFL-best 1,631 yards and get named first-team All-Pro as a rookie by accident.

“When I look at Zeke, something I want to get better at that he does is downhill running, understanding situations and taking what the defense gives you. Just lowering your shoulder and doing that,” Barkley said. “Sometimes in college, I would try to make that three and four [yards] and try to make it 60 sometimes.

“Just being more aware of the game. He’s a very physical runner. He’s big. He’s jacked. And then he can come out and juke you and catch the ball out of the backfield. And the way he sets up his screens. The patience in his screen game is really good.”

Barkley isn't too shabby in that regard, either. He was drafted second overall -- two picks higher than Elliott -- for a reason.

Elliott believes his success with the Cowboys contributed to the Giants pulling the trigger on Barkley in the draft.

"It definitely might have," Elliott said. "But he’s a phenomenal player. He’s a great player, definitely -- I think, honestly, was the best player in that draft. He deserved to be picked that high."

Barkley is now trying to replicate Elliott’s on-field success early in his career, particularly his rookie year. It’s possible. The past two NFL rushing leaders (Elliott and the Kansas City Chiefs' Kareem Hunt) were rookies.

Barkley’s 106 yards rushing on Sunday was the third-highest total in Week 1, despite him being hit at or behind the line of scrimmage on seven of his 18 rushes. His 68-yard touchdown -- during which he broke a pair of tackles, ran through other contact and surprised Jacksonville Jaguars defenders with his speed -- validated his teammates’ belief that he can have that Elliott-like rookie season.

“I’ve seen all that. And I played him in college,” Apple said. “He’s got that hungriness and he wants to go out there and dominate. Very hard [to tackle]. He’s strong and he’s shifty. So he’s going to be a great one.”

Just like his friend, who now also happens to be his division rival.

ESPN Cowboys reporter Todd Archer contributed to this story.