New Orleans drafted Andrus Peat to be the right tackle of the future, the heir apparent and an instant competitor to veteran Zach Strief.

Now, Peat has to be the left tackle of the present.

The No. 13 pick of the 2015 draft is slated to make the first start of his career against Philadelphia on Sunday on the left side, forced into the starting lineup by a left knee injury to Terron Armstead that has kept the Saints’ best offensive lineman out of practice all week, even though he was able to battle through it to finish the win over the Dallas Cowboys last week.

“I think his confidence is good,” Saints coach Sean Payton said. “Shoot, he’s a first-round pick at left tackle, and I think he’s prepared. He’ll be ready to go.”

Peat, unlike most of the Saints rookies on the other side of the ball, spent the first month of the season getting his feet wet, rather than being thrown into the fire.

The Stanford product is averaging 7.25 snaps per game on offense, mostly as an extra tackle brought in to play tight end in heavy sets, although he got five snaps against the Cowboys at left tackle after Armstead went down at the end of the first half.

New Orleans envisions Peat as a right tackle at the NFL level.

For his first start, though, Peat gets a chance to settle into his comfort zone. Until this season, he had spent all seven years of his football career on the left side, all the way through his time at Corona del Sol High School in Tempe, Arizona, and three years at Stanford.

Flipping back to the left side for this start feels natural.

“It’s been pretty smooth, especially since I’ve always played left tackle,” Peat said. “So it really hasn’t been a big problem going back.”

Peat, unlike rookie linebackers Stephone Anthony and Hau’oli Kikaha, who have been in the starting lineup since the first preseason game, had some growing pains in training camp. A massive tackle at 6-foot-7 and 316 pounds, Peat reported to camp out of condition, and he struggled at times, overwhelmed by the physical toll of training camp.

The Saints responded by handing Peat more preseason snaps than any other offensive lineman, forcing him to get into shape.

Early on, Peat drew heavy criticism from fans and media as he struggled to handle outside rushers early in camp. But the rookie said he wasn’t paying attention.

“I just try to get better, take coaching and do what they’d have me do,” Peat said. “I don’t think too much about outside stuff or what people are saying about me.”

Once he got into shape, Peat started making strides.

“He is someone that we feel like has made quite a bit of progress; the snaps he’s played at tight end the other night helped us tremendously down the stretch, and then also the snaps he played for a brief period of time at left tackle,” Payton said. “I think the early snaps in the first quarter of the season have been real positive.”

Peat’s biggest strides have been made in the mental game.

In the NFL, the correct technique for every play call can change based on the way the defense is aligned, and Peat has been asked to learn new footwork and techniques since joining the Saints, even though Stanford played a pro-style offense.

Now that he has had a month of practices, his teammates have seen a difference.

“There’s a lot of nuances in offensive line play in the NFL,” Strief said. “That’s why the transition’s tough. I think he understands what we’re trying to do a lot better than he did. Being a little gray in terms of on this play, you’re using this technique, whereas that play, with a different look, it’s a different technique, it’s a lot of thinking, a lot of reacting — which is not a good way to play.”

Peat feels comfortable enough in the Saints offense now that he can spend most of his preparation studying the Eagles’ pass rushers.

Blocking edge rushers like the Eagles’ Connor Barwin and Brandon Graham requires plenty of film work, identifying what moves they like to use in big moments, how they set up moves and what tendencies can be exploited. Peat, as the third tackle, has spent the first month taking a close look at every edge rusher on the opponent, because he might have to go into the game on the right or left side at any moment.

Now that he knows he’s starting, he could focus on the blind side, but Peat knows that could hurt him against NFL teams that like to move their best rushers all over the formation.

“I’ll still study both rushers, because they could easily flip sides, play both sides, so I’m just prepared for whoever’s lined up there,” Peat said. “I’m studying all the outside rushers.”

Peat admitted he’s excited. The highest pick of a Saints rookie class that already has been highly productive is getting his chance to prove he’s ready.

“At some point, they go,” Payton said. “At some point, the rookie kicker kicks, or the young receiver goes, Terron Armstead a few year ago at Carolina. At some point, they go.”

Peat’s time has come.