When the Steelers selected Troy Fautanu and Zach Frazier with their first two picks in the 2024 NFL Draft, many assumed the team would have two new starters on their offensive line when they opened the regular season in Atlanta.

That will be the case, but it won't necessarily be the two players most thought.

Steelers head coach Mike Tomlin said Tuesday that left guard Isaac Seumalo will miss Sunday's regular season opener against the Falcons with a pectoral injury suffered during practice last week, meaning second-year pro Spencer Anderson will make his first career start in Atlanta.

Anderson, a seventh-round draft pick in 2023, will line up next to Frazier at center, giving the Steelers two first-time starters on their offensive line.

Coupled with the other three starters, Dan Moore Jr. at left tackle, James Daniels at right guard and second-year player Broderick Jones at right tackle, it will add up to a very young line opening the season on the road.

"There's a lot of meat on that growth bone, and we've seen a lot of it, to be quite honest with you, for several reasons. We had some young guys that drafted high in the Draft and showed the NFL is not too big for them, and I imagine they'll continue to show that and continue to grow with exposure," Tomlin said at his weekly press conference at the UPMC Rooney Sports Complex. "But we've also got some second-year players like Broderick and Spencer, and that second lap around the track, it's reasonable to expect growth and development because of the knowing component. So we've challenged them in that regard, and they've responded.

"We've got some talented young people, so it makes for an exciting mix."

Exciting and lacking some experience. With Seumalo out of action on what Tomlin called a "week-to-week" basis, the Steelers will be without his 77 career starts. Daniels leads the group with 80 career starts, while Moore has 49 and Jones 11.

But the Steelers are excited about Frazier, a second-round pick out of West Virginia, at center and see Anderson as an up-and-coming young lineman they can build around, despite his late-round pedigree.

Tomlin compared Anderson's trajectory to that of former Steelers and current Arizona Cardinals offensive lineman Kelvin Beachum, a seventh-round pick in 2012, who is entering his 13th season in the NFL.

"His versatility was a calling card that allowed him to sustain, but the longer he's here, you'd better specialize in a certain area," Tomlin said of Anderson, who has lined up at all five line positions in practice and the preseason. "Really his growth and development kind of reminds me a lot of Kelvin Beachum, if you remember years ago. Versatility was kind of his calling card, but then he settled into the tackle position and went on to -- Beach might still be playing. I think he is.

"Spence will be fortunate if he has a Kelvin Beachum-like story."

How long it lasts remains to be seen. But Tomlin was optimistic regarding Seumalo's injury, which was initially feared to be much worse.

"(We're) really optimistic about his returning sooner rather than later," Tomlin said.

Good news on the injury front: Not only was the news on Seumalo better than expected, Tomlin said Tuesday the team could be getting some other players who missed significant portions of the preseason back from injury in time to participate against Atlanta.

"We had a couple of guys working in a partial capacity yesterday in our bonus day, and we expect that to continue and increase as we push towards game time," Tomlin said. "Those guys are Roman Wilson and Troy Fautanu. We're optimistic about both guys. Jaylen Warren can also be included in that discussion, along with Cory Trice."

Fautanu has been out since the preseason opener, when he suffered a sprained knee.

The first-round pick had been working at right tackle prior to his injury, but with him out of the mix, the Steelers have stuck with Moore at left tackle and Jones, their first-round pick in 2023, at right tackle.

"Obviously he's worked a lot at right," Tomlin said of Jones. "We're going to continue to watch that as we progress through the week because versatility has been an asset for him and us."

Wilson, a third-round pick, missed all of the team's preseason games with an ankle injury, while Warren suffered a hamstring injury in the team's second preseason game against the Bills. Trice suffered a groin injury in the team's preseason finale against Detroit.

Faith in the wide receivers: Tomlin said he challenged the team's wide receiver group early in training camp to show him they had the capability to help offseason the trade of Diontae Johnson in the offseason in a deal to acquire cornerback Donte Jackson.

Despite the team's publicized interest in acquiring Brandon Aiyuk via trade with San Francisco, Tomlin said he was happy with how the team's wide receiver room responded.

Tomlin is confident in the abilities of third-year player George Pickens, but he wanted someone else to step up and fill the void left by Johnson's departure.

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"I'm comfortable with the performance of these guys," Tomlin said. "(I) had some questions, even dating back to spring, and to be quite honest with you, I probably went into the receiver room a couple weeks into camp and told them that. I just believe in being really transparent.

"But the consistency with which those guys performed in Latrobe and with team development has made me more comfortable, and specifically I'm talking about Scotty Miller and Van Jefferson. I just can't say enough about the consistency with which they've performed, their floor. They behave like veteran NFL players, and that's provided some comfort in the midst of the transition that comes with dealing with new people and getting acclimated in that way."

Miller led the Steelers with eight receptions for 74 yards in the preseason. Jefferson, a former second-round pick of the Rams, listed as the starter opposite Pickens on the depth chart, had six receptions for 57 yards.

Both were with the Falcons last season with new Steelers offensive coordinator Arthur Smith.