Any day you ask new San Francisco 49ers linebacker Kwon Alexander how he is feeling, he will confidently respond, "Legendary."

That's more than a description to Alexander. It's a mindset.

"I don't like to use the word ['good'] because I'm trying to be better than that," the linebacker said in July. "So I use ['legendary'] just to keep my mindset where it needs to be, and that's what it is."

Alexander, like other 49ers teammates, is returning from an ACL injury. His was suffered during Week 7 of last season, and the linebacker landed on injured reserve on October 22, 2018.

Alexander became a free agent in March, and the 49ers made him one of their first signings of the new league year. While there was some concern that he might not be ready for the start of the regular season, his rehab progress seemed encouraging, and the linebacker was cleared to practice at the start of training camp.

The 49ers are in the Denver area to practice against the Broncos before the two teams square off on Monday night. A reporter asked Alexander how his knee feels. The response should not be surprising.

"My knee feels legendary," Alexander answered. "I'm back out there, getting back to my style, running fast, and just trying to make plays. That's what I'm trying to do."

After practice, defensive tackle DeForest Buckner discussed the energy Alexander brings to the defense and couldn't help using the linebacker's coined phrase while doing so.

"He brings a lot of energy," Buckner said. "Every day is legendary for him. He definitely comes out ready to come downhill and hit somebody, and that's the type of energy we need on defense."

Alexander considers second-year linebacker Fred Warner and himself to be the leaders of the defense. Having energy is part of the job description.

"Linebackers, we've got to take control, be vocal, be loud, have the energy, make everybody feed off you, and that's what we're trying to do," Alexander said.

The linebacker added, "Fred, I [keep] telling him, 'You've got to match my energy today,' stuff like that. And he goes out there and [does] it. He [is] very vocal, talking tough. He's out there making crazy plays, and he's going to keep doing that."

Defensive coordinator Robert Saleh has noticed Alexander's impact on Warner but didn't want to boast too much about the group's attitude on the field.

"Fred's coming into his own," Saleh said after practice. "He wanted to, obviously, last year as a rookie, but having Kwon with him, because Kwon's very vocal, it's bringing out Fred. Fred's very confident and just a good football player, so they do what a linebacker group is supposed to do, so I won't pump them up for doing what they're supposed to do. It's a good group, though."