For different players, training camp has different functions. For Daniel Muir, a nose tackle the Houston Texans signed just before camp, it's the next stop in a career throughout which he's watched and learned from future Hall of Fame players -- or players he thinks should be in the Hall of Fame.
It started with Brett Favre during Muir's first season.
"My rookie year I was a little ... you could say starstruck," said Muir, who played in Green Bay in 2007, making the roster after going undrafted out of Kent State. "My locker was four lockers down from Brett Favre, I was like, 'This is Brett Favre’s locker.' But I mean, it was awesome to really get to know him. ... He kept the game fun."
As a rookie, Muir watched defensive end Kabeer Gbaja-Biamila break the Packers' team sacks record.
"Kabeer, he was a guy that was gonna work on his craft," Muir said. "He knew what he did well and he was going to work that. Charles Woodson, amazing guy to be around. One thing about him is he knows how to take care of his body."
Waived after the 2007 season, Muir went from one successful organization to another, catching on in Indianapolis, where he stayed for three seasons.
"I was always a bigger guy, but they really saw my explosion and were like, 'We’re going to teach you how to rush,'" Muir said.
He veered away from talking about Indianapolis before realizing he'd forgotten one important Colt: receiver Reggie Wayne.
"It’s like that guy gets younger every year," Muir said. "You want to talk about somebody who just works. You see him out there running routes, you may think he’s just jogging running routes, but he’s counting his steps."
Muir became a bit of a journeyman after his time with the Colts, which ended in 2010. He spent periods with the Rams, Jets and Chiefs, in addition to second stints with the Colts and Packers, mostly during the offseason or training camp.
The average NFL career is shorter than Muir's has been. It hasn't been a glamorous one, but he's lasted, in part because of the lessons he's drawn from the great players he sees. Their common theme? Hard work on their craft. As he put it, he learned to "shut my mouth" and listen.
He's done a lot of that in Houston, where he's played in 17 snaps in each of the Texans' two preseason games. When safety Ed Reed was in town, Muir embraced the opportunity to learn from him, too.
"He was just remembering certain plays," Muir said of Reed. "'On this play you should fit here,' or 'You should be here on this play.' A lot of times guys will take that the wrong way, but I didn’t take it like that. He’s a field general back there. He sees everything going on in front of him. He knows how guys should fit, where guys should be. That’s how he’s had so much success. I take that and I listen to it. We’ve had a lot of conversations since I’ve been here and he’s helped me out a lot."
It won't be easy for Muir to stick around with the Texans. Whether or not that happens, though, what he learns will never leave him.