1st start for rookie Parker

development for the Raiders on Sunday.

In Parker and left tackle Kolton Miller, the Raiders are expected to start rookies at both tackle positions for the first time since at least the AFL-NFL merger in 1970, according to the Elias Sports Bureau, when they visit the Chargers at the StubHub Center in Carson (Los Angeles County).

Miller, this year’s 15th overall pick, has started all season protecting quarterback Derek Carr’s blind side. Parker, the 65th overall pick out of North Carolina A&T, had played eight snaps on special teams in Weeks 1-3 before replacing Penn and playing 57 snaps against the Browns.

“That’s the NFL,” Miller said Friday. “Next man up. And I know he’s been staying up on top of plays. So, yeah, I think we’re ready.”

For part of this offseason, Parker said, he and Miller roomed together while transitioning into the NFL. Most of their conversations were about football, he said, but included “a little bit of life stuff, too.”

“We’re pretty much the same person, besides the skin color,” Parker said, grinning. “We’re really big on balance and we’re very calm, collected people in general. He’s just like me. He doesn’t say a lot, I don’t say a lot. We just get the job done.”

Parker might have competed for a starting job in training camp with Penn recovering from foot surgery. But an ankle injury sidelined Parker for about two weeks, delaying his jump from college ball to the NFL.

If not for the injury, Parker said, he felt he “could’ve been in a much better position to help the team earlier.” The injury led to him getting more practice reps at right tackle after playing solely left tackle in college.

“We knew he had the talent level to play here at this level,” offensive coordinator Greg Olson said. “But there’s always a transition I think from college to the NFL. We’re happy with where he’s at right now, but he still has a ways to go as well.”

That was clear against the Browns. After replacing Penn, according to Pro Football Focus, Parker played 39 pass-blocking snaps and allowed two sacks and four total pressures. He admitted that he missed a protection read on one sack and said at one point he was taken aback by the power of Browns defensive end Myles Garrett.

“I actually went to the bench and asked Kolton, ‘Why you ain’t tell me he was that strong?’ ” Parker said. “He said, ‘You didn’t see me getting bullrushed the whole game?’ ”

The rookies’ sharing a field almost didn’t happen. Miller went down on a play in the first half — he was limited in practice this week with a knee injury — but he credited Carr with helping him shake it off.

“When I got the injury, I was like, ‘Damn,’ ” Miller said. “And then Derek was like, ‘Come on, Kolton, get up!’ I was feeling, like, a breath of life. I just popped right up.”

After facing a Cleveland defensive front that brought, in Olson’s words, “exotic pressures,” the Raiders this weekend will see a Chargers defense feeling the absence of injured defensive end Joey Bosa. The Chargers are tied for 22nd in the NFL with eight sacks (the Raiders rank last with five) as their rushers “haven’t won enough one-on-ones,” head coach Anthony Lynn said.

“People have given (defensive end) Melvin Ingram a lot of attention, as they should, and it has freed some guys to go in on the back side and we just haven’t gotten it done,” Lynn said on a conference call this week. “We’ll make adjustments and we’ll create pressure different ways.”

Miller said the Chargers still “have power on the edges,” and he and Parker are “both going to be tested in that regard this week.”

“This is our chance to ball out,” Miller said, “and make a name for yourself.”

Matt Kawahara is a San Francisco Chronicle staff writer. Email: mkawahara@sfchronicle.com Twitter: @matthewkawahara