As a junior at Texas Christian University, Halapoulivaati Vaitai walked through a Dallas-area shopping mall with his cousin when the cousin stopped him mid-step.

"Hey, that's Jason Peters!" the cousin said.

At 6-foot-4 and 328 pounds, Peters doesn't easily blend in. But he works in Philadelphia and wears a helmet, so it's not a celebrity sighting that would often resonate in Dallas. Except Vaitai, who is 6-foot-6 and 320 pounds, played offensive line just like Peters. He studied Peters' film when learning technique. He wanted to meet Peters, so he approached the future Hall of Famer. Peters asked where Vaitai played and the two spoke for a few minutes.

"Work your butt off," Peters said, "and you'll be up here."

One year later, the Eagles drafted Vaitai in the fifth round of the NFL draft. Peters found Vaitai's number and called his new teammate.

"Remember me?" Peters asked.

"I didn't know it was going to be literally here," Vaitai said Friday, remembering the encounter.

Vaitai didn't just become Peters' teammate. He's now Peters' replacement in the starting lineup. Peters tore the anterior cruciate ligament and medial collateral ligament in his right knee, sidelining the 35-year-old for the season. His future with the Eagles and in the NFL is unknown. It devastated the locker room, where Peters is one of the most respected figures. But the Eagles must guard against it have lingering effects on the season, which is off to one of the most promising starts in franchise history with a 6-1 record entering Sunday's game against the winless San Francisco 49ers.

That's where the 24-year-old Vaitai comes in. The Eagles decided against moving Lane Johnson from right tackle to left tackle. Johnson's playing well on the right side and some of the top pass rushers the Eagles face will come from Johnson's side. So the Eagles are turning to Vaitai to protect Carson Wentz's blindside.

"Nobody replaces Jason Peters," Vaitai said. "It's going to be hard to do. But I've got an opportunity to play, so I'm going to take this time and play for JP and use what I've been taught and play for him."

Some of what Vaitai has been taught has come from Peters, who is known to help apprentice young players. When Peters sat in the cart after the injury on Monday, Peters already started sharing tips with Vaitai and offering feedback to offensive line coach Jeff Stoutland.

On Tuesday morning, with the knowledge that his season was finished, Peters sought Vaitai. He offered the same advice that he gave Vaitai in the Dallas shopping mall and during the post-draft phone conversation.

"In his own words, 'Work your a– off.' A direct quote from Jason Peters," Vaitai said. "That's the best advice I've got. He can tell me anything else, but if I just work my butt off…you'll be OK."

Different year, different player

This is not last year. The Eagles made that clear when Vaitai entered the starting lineup for Johnson during an Oct. 12 win over Carolina. The Eagles' 2016 season unraveled when Vaitai replaced Johnson during Johnson's 10-game suspension. It wasn't entirely because of Vaitai, but Johnson's absence and playing a fifth-round pick at right tackle with a rookie quarterback was a bad combination.

"Got more experience and the game kind of slowed down for me a little bit, but I've still got a lot of improvement to do," Vaitai said.

Vaitai has now started seven games and played 610 career offensive snaps. The Eagles are confident in the player they're putting into the lineup.

"They rally around a guy like Big V, now who, listen, he's not a rookie," Pederson said. "He's not that spring chicken who is playing for the first time. He played significant time last year. He's played this year already."

Before the Carolina game, Pederson cited all the pass rushers Vaitai has already blocked and situations he encountered. He faced Ryan Kerrigan and Chandler Jones. He started on the road in Seattle. Vaitai might not be a household name in Philadelphia, but in the locker room, he's more known than he was one year ago when he never started a game.

Vaitai admitted he's "a lot more comfortable" than as a rookie. Although most of his experience has come on the right side, he played left tackle at TCU and at different times this season. There are technical adjustments he must make, but it's not foreign to him.

"Just got to flip everything in your head," Vaitai said. "JP always says, kick to your spot, arms inside, you'll be OK."

The Eagles aren't expecting him to play as well as Peters. They know what they're missing and how difficult Peters is to replace. The team is honest about it; it would be an insult on Peters to say otherwise. Offensive coordinator Frank Reich thought Vaitai played "solid" in Peters' place during the second half on Monday night, and the Eagles would probably take solid.

"That's a tough thing to do, to walk in and not only just to play that position, but filling in in those shoes right there for Jason Peters, but he did a good job," Reich said. "Now, I'm not going to lie, Jason Peters is a rare player. I have no problem saying I've been around this game for 30 years, and I've been around some great offensive linemen, a lot of great offensive linemen. I mean no disrespect to any of them because there are a lot of great ones, but Jason Peters is the best one I've ever been around."

Peters has started every game Wentz played in the NFL. It's unclear how, or if, Wentz will be affected by the change at left tackle. Johnson's absence appeared to affect Wentz last season, but Wentz is a year older and he has more experience with Vaitai. Since the summer, Wentz has touted the offensive line depth. Pederson is willing to roll protection help to Vaitai's side if needed. Wentz said a quarterback must rely on a feel for the pass rush in the pocket. Of course, it's easier to say that when you know Peters is there.

While outsiders wondered if the Eagles would pursue a tackle via trade or free agency, Pederson has been unwavering since the hours after Peters' injury that Vaitai would become a starter. The Eagles want to build a culture of promoting from within, and Vaitai's experience in the scheme helps. Although they're willing to make a change when needed – look at the Isaac Seumalo experiment as an example – the Eagles appear committed to giving Vaitai a chance to succeed at left tackle.

"He hasn't really got to play a full year," Johnson said. "All he needs is playing experience and he's going to be good. That's all it is."

Future starts now for ‘easygoing guy’

The Eagles entered the 2016 draft committed to addressing offensive line depth. They went two years without taking a lineman, and the internal pipeline was bare. Vaitai appealed to the coaching staff because of what Howie Roseman identified as "rare tools" that would compel the coaches to "take him anywhere in the draft." Stoutland even visited Fort Worth, Texas, to work out Vaitai. They thought Vaitai needed development, but they identified a potential future starter.

When Pederson was asked Friday if the Eagles inserted Vaitai at left tackle with the eye toward the future, he said he hasn't considered that – only this week. But an Eagles line that was aging when Pederson inherited it will start a quintet on Sunday without a player in his 30s.

Vaitai could build a long career in the NFL, although he already has post-career ambitions. A criminal justice major at TCU, he aspires to work for the Department of Homeland Security. He could discuss North Korea policy options in the same conversation as the 49ers' pass rush. He's endeared himself to his teammates with an easygoing personality that doesn't ride a pendulum of emotions.

"You can't [tick] him off," Johnson said. "Laid back, chill. I've never seen him [ticked] off, no matter the situation. Just an easygoing guy."

Teammates call him "Big V." Few in the building attempt "hal-lah-poo-lee-VAH-tee"; Stoutland tried during an offensive line meeting last year before deciding to stick to "Big V." His brothers are named Kevin and Will, but Vaitai was given the name of his father's cousin.

The next step is to see how soon Eagles fans can pronounce "Halapoulivaati." He might never earn the reverence of Peters, but that's not the standard to which the Eagles are holding him. They're not trying to replace Peters; they just need Vaitai to be steady enough to keep winning.

"The rest of the season, I'll be playing for Jason Peters," Vaitai said. "Try to make him proud."