GREEN BAY—The moment wasn't lost on the rookie.

On his first day in pads as an NFL offensive lineman on Sunday, lining up for his first one-on-one rep in the pass-rush/pass-blocking drill, David Bakhtiari saw Clay Matthews sizing him up.

"I knew it was him," Bakhtiari said of one of the league's premier pass rushers. "It was just, I'll see what I've got."

Turns out Bakhtiari had plenty. Playing left tackle on this particular snap, he shot to the left out of his stance to protect the edge and then braced himself for Matthews' bull rush.

Amidst the repeated barks of "Get him, rook!" from Offensive Line Coach James Campen, which Bakhtiari said he didn't even hear, the fourth-round pick from Colorado did his job. Matthews didn't get to the spot that marks the imaginary quarterback in the drill. The "rook" had won.

The victory highlighted an impressive first day in pads for Bakhtiari. Flipping back and forth between left and right tackle, he won his other reps against younger pass rushers, too.

It's still very early, obviously, but after three days, Bakhtiari couldn't have asked for a better start to camp. He looks composed and confident, making it a good bet he'll be heard from more as camp continues.

"I pretty much got out all my jitters in OTAs, so I wasn't really worried even at the first practice, because I got a sense of what certain guys do and don't do," he said. "I was pretty comfortable."

He credits Matthews for helping with that. The two actually got to know each other before Bakhtiari was drafted by the Packers, as they worked out together at ProActive Sports Performance in southern California.

Over the winter, Matthews had been working out with Bakhtiari's older brother, Eric, a linebacker who has bounced around to various NFL teams over the past five years and most recently played with San Francisco last season. After the scouting combine and his pro day, Bakhtiari went to ProActive to work out with his brother and met Matthews.

Following the draft, with the knowledge they'd be teammates, their conversations naturally became more frequent, and Bakhtiari has appreciated having a veteran player like Matthews to turn to from the get-go.

"He made the transition really easy," said Bakhtiari, adding that Matthews was joking with him on the field after their faceoff in the one-on-ones. "He's been not only a great teammate but also a really good friend."

Where Bakhtiari's rookie season goes from here remains to be seen. In practice, he's currently the No. 2 left tackle behind Bryan Bulaga and, barring injury to Bulaga, won't be playing there in 2013.

But at right tackle, he could be in the mix for the starting job, though right now the snaps with the No. 1 unit are being split between Marshall Newhouse and Don Barclay.

Bakhtiari said switching sides from play to play doesn't bother him. He did some of that in college and it only took a couple of days of camp before flipping back and forth didn't feel "unorthodox." It's just another way he's made a notable first impression.

"I see it as just go out there and show what I can do," he said. "If they call me up to be on the (first) team, I just want to make sure I'm ready to go out there and compete."

That one-on-one rep against Matthews showed Bakhtiari may be ready much sooner than the average rookie. Even though he downplayed it a bit, he'll certainly take it.

"I guess I got him on that one, but I know he ain't worried about it," Bakhtiari said. "We've got a lot more battles to come."