GREEN BAY – The football encyclopedia is permanently open. Marcedes Lewis made that promise during the infancy of what turned out to be a 13-year NFL career…and counting.

As a first-round pick in 2006, the 6-foot-6, 267-pound tight end had to learn a lot of things the hard way. After developing into a Pro Bowler, Lewis vowed to keep an open-door policy to any young player who wished to tap into his knowledge bank.

On the field, Lewis views himself as a "player-coach." Have a question about the offense? He's quick with a reply. Need advice on a blocking technique? Look no further than the guy who's been heralded as one of the best of his generation.

There are no secrets with the 34-year-old. Just ask Emanuel Byrd, Robert Tonyan or any of the other young tight ends on the Packers' roster this summer.

"It's tremendous having a guy of his stature who's been in the league for 13 years and the success he's had in the game," said Byrd, a former undrafted free agent who finished last year on the Packers' 53-man roster. "Just how consistent he is with it every day is mind-blowing. And getting to talk to him as an older guy in this league while trying to find your way in the league is great. It's more than you could ever imagine."

Tonyan, who signed to the Packers' practice squad last December, also has taken advantage of Lewis' presence in the tight ends' room, particularly when it comes to blocking.

A former college receiver, Tonyan (6-5, 237) was a novice when it came to the nuances of his new position at the beginning. Paired with Green Bay tight ends coach Brian Angelichio during the last month of the 2017 season, Tonyan worked to refine his blocking technique and footwork.

He's made significant strides this summer. While Tonyan caught his first NFL touchdown last week against Pittsburgh, he knows there's more to playing the position than catches.

That's where Lewis comes in.

"I would say from a blocking standpoint and me starting from zero, having one of the best to ever do it at our position, you can't really ask for much better than that," Tonyan said.

Lewis isn't in Green Bay just to teach. He wouldn't have signed with the Packers back in May after 12 seasons with the Jacksonville Jaguars if he wasn't convinced he could still play.

A veteran of 170 career regular-season games, Lewis remains one of the league's preeminent blocking tight ends. The Packers believe his ability to play in-line is a perfect complement to the style of fellow veterans Jimmy Graham and Lance Kendricks.

Head Coach Mike McCarthy acknowledges he hasn't had a blocking tight end quite like Lewis in his time in Green Bay. There have been many who are willing, but few who consistently can shut down defensive ends like Lewis has throughout the course of his career.

A force in the team's run periods in camp, Lewis also doesn't blink when he says he still can stand toe-to-toe with the NFL's best rushers when the situation calls for it.

"I can pass-block anybody in this league one-on-one," Lewis said. "I'm confident in that. I take a lot of pride in that. I think that's part of the reason they brought me here."

Lewis also can still make defenses pay as a pass-catcher. He hauled in a 23-yard completion last week against Pittsburgh and held onto the ball despite Steelers cornerback Coty Sensabaugh collapsing over the top.

The wily veteran did it again during a team period in Monday's practice at Nitschke Field, catching a pass from DeShone Kizer downfield in traffic for a big gain.

The Packers are hopeful the large catch radius of both Lewis and Graham could be a big difference-maker in the middle of the field and red zone this season.

"I think how we are constructed now, our offense, it can be deadly as long as we pay great attention to detail," Lewis said. "It's easy to sit here and talk about it all day. At the end of the day, we still have to go out there between the lines and be where we're supposed to be when we're supposed to be there, and be accountable when your number is called."

Although Lewis isn't as expressive as Graham on the field, he isn't afraid to be vocal.

After Tuesday's practice, Aaron Rodgers commended Lewis for a conversation he had with the team after a recent walk-through. So far, the veteran tight end has been one of several offseason additions who have made an early impression on the Packers' quarterback.

"It was fantastic," said Rodgers of Lewis' talk. "To have a guy like Marcedes with his track record, his credibility and his career performance, guys listen. I need that as a leader on the team. I need those guys to step up and help out in the leadership roles. It's been great having those guys because they have really bought into what we're doing and they're pros."

The Packers featured their two tight-end packages prominently against the Steelers, opening the first series with Graham and Kendricks and later using Kendricks and Lewis in tandem.

Green Bay hopes their differing skill sets force defenses to make a difficult choice in how to defend its offense – go big in a base front and possibly get exposed in the passing game or go small with defensive backs and possibly get gashed on the ground.

"That's part of what I do. I take a lot of pride in being an all-around tight end," Lewis said. "There aren't a lot like me anymore. Whether it's pass-blocking or run-blocking one-on-one, whatever it may be I just want to be accountable."