Alexander is known for his energy. Even before he was cleared to participate in practices once he recovered from tearing his left ACL last year, Alexander would jump up and down on the sidelines every time the defense made a positive play.
Warner, who was more reserved in his rookie season, has come out of his shell during the preseason. Alexander is at least partially responsible for that evolution.
"I've been telling him, you've got to match my energy today, and he goes out there and does it," Alexander said. "He's very vocal, talking to us. He's out there making crazy plays and he's going to keep doing that."
That liveliness was very evident in the first of two joint practices with the Denver Broncos.
"It's way more exciting for us than playing against our squad the whole time," Alexander said. "Now to go out here and compete against the other guys, talking a little smack and competing, that's what we were out there doing."
Defensive coordinator Robert Saleh has noticed the difference in Warner's behavior, and he is excited to see it develop. Saleh likes the balance between the two leaders in the linebackers room.
"Fred is coming into his own," Saleh said. "He wanted to obviously, last year, as a rookie, but having Kwon with him because Kwon is very vocal, it's bringing out Fred.
"Fred is very confident, rightfully so. He's a good football player, so they are what a linebacker group is supposed to do. So I don't over-pump them up for being what they're supposed to be. It's a good group."
Warner's enthusiasm and ability were on full display Friday, especially when he pressured Broncos quarterback Joe Flacco during team drills. He forced Flacco to throw without a full look at the field on one play, and the ensuing pass went right into the hands of safety Tarvarius Moore for an interception.
That's all part of a linebacker's responsibilities, according to Alexander.
"We are the leaders of the defense," Alexander said. "You know linebackers have to take control, and be vocal, and be loud, and have the energy and everybody will feed off of you. That's what we are trying to do."
The 49ers linebackers even have a new name for themselves this season. They actually break down their position group huddle calling themselves the "hot boys."
"It's just something that we made up as a linebacker group," Alexander said. "We want to be hot every day so when somebody is cold, we pick them up, we stay hot. That's how it is. We just hold ourselves accountable and everybody's got to have energy in the linebacker group. That's what it is."
How 49ers' Kwon Alexander is bringing out more energy in Fred Warner originally appeared on NBC Sports Bay Area