Rookie tackle Miller impresses early

All-Pro left guard Kelechi Osemele has spent most of two seasons with the Raiders playing alongside a grizzled left tackle in Donald Penn who’s entering his 13th NFL season.

So far this camp, Osemele has lined up next to a player preparing for his first in firstround draft pick Kolton Miller. Osemele, in turn, is still learning about Miller, but said after the team’s second full practice Saturday that his early impressions of the 6foot-8 rookie have been favorable.

“Kolton looks real good right now,” Osemele said. “We’ve still got a lot of work to do. It’s our first time working together, so just knocking the rust off on double-teams and stuff like that, making sure we’re going the right way, the little things rookies go through.

“But physically, his development, his understanding of our play-calling, the game, our scheme: He’s way ahead of where I would’ve been at this point in training camp my rookie year.”

Miller, the 15th overall pick in April’s draft, is working with the first-team offense as Penn works his way back from foot surgery. It’s a notable situation given Miller also represents a potential successor to Penn, who is 35 and has two seasons left on his contract.

The Raiders have an open job at right tackle as well but had Miller work on the left side for all of spring practice. Penn has indicated he does not intend to hand the job to Miller, tweeting the word “motivation” on draft night and reportedly making a piqued phone call to head coach Jon Gruden. Yet, Penn has also taken a role in Miller’s development while sidelined.

While the offensive line ran position drills at Saturday’s practice at Napa’s Memorial Stadium, Penn stood nearby watching and spoke to Miller a few times between reps. Asked which teammates he has leaned on for advice, Miller named right guard Gabe Jackson and Penn.

“Especially Donald Penn — that happened a lot in the spring,” Miller said. “I’d be in the back and he’d be telling me, ‘You can be doing this and sitting back.’ He has a lot of tips for me, especially him being as experienced as he is.”

Miller played just one full season at left tackle at UCLA, but the Raiders were attracted to him by what Gruden termed his “huge upside” and his mix of athleticism and size (6-foot-8, 309 pounds). Osemele said that given that frame, Miller’s ability to move “takes you by surprise.”

“He’s real athletic, man,” Osemele said. “I don’t think it’s ever going to be a case of him getting beat (by) somebody just running around him or anything like that. With a guy like that, it’s going to be him working on his anchor, just being in the weight room and getting stronger and stuff.”

Miller said he did put on weight this summer, though he declined to say how much because “it varies.” Others, including quarterback Derek Carr, noticed a difference.

“You can tell that he put in a lot of work in the weight room before he came back,” Carr said. “He came back and he’s strong, ready to take those bull rushes. As a tall guy you know that’s coming, you know the bull rush is coming. But he’s ready. He looks really good.”

In April, Gruden said one reason the Raiders had drafted two offensive tackles was the glut of talented pass rushers they face in the AFC West. The Raiders themselves moved Bruce Irvin to more of a defensive end role this summer to enhance their own pass rush, and while working with the first team, Miller figures to see plenty of Irvin coming off the edge in practice.

“He’s blocking a beast over there,” Gruden said. “Bruce Irvin is one of our captains right now, and he’s going to test Miller every day.”

Miller said he’d welcome the challenge — especially after the team dons pads for the first time Sunday.

“I think it can only help me,” Miller said. Irvin “has a lot of tools that he uses, a lot of moves, which means you have to really hone your craft. He wants you to mess up. So that’s something you have to focus on and make sure you don’t do, because then he can get you.”

Miller said he benefited from practicing with other rookies last week before veterans reported to camp. He’s admittedly “not a real talkative guy” but said he felt more comfortable making calls and was “pretty vocal out there” Friday. It’s part of the learning curve of a player for whom the Raiders have high hopes.

“As far as the framework of being an elite left tackle, he has the tools there,” Osemele said. “I think it’s really up to us to get him where he needs to be.”

Paul Chinn / The Chronicle First-round pick Colton Miller, seen at a May mini-camp, said he put on weight and has been taking reps at left tackle.