Landry who has set the tone with his physical nature. His aggressiveness sets the standard in the secondary.
He also doubles as a mentor for the other defensive backs.
"It's something I've embraced," Landry said. "If I'm the guy people look for, I'm all for it. I'm just trying to lead by example and play my game. I'm always trying to fly around to the ball. I'm not trying to be the leader. I just want to be a positive influence out there."
Last season, Landry was voted by his teammates as the winner of the Ed Block Courage award for how he came back from a spinal cord concussion that required surgery.
One year removed from a scary injury suffered in the second game of the season, Landry wound up registering 89 tackles and tied for the team lead with four interceptions.
Other than the surgical scar on the front of his neck, Landry said he doesn't think about the injury.
"It never crosses my mind," Landry said. "After a certain time last year, I was done with it. Once I got the kinks out, it was fine."
Zbikowski has started both preseason games and appears to have separated himself from former Pro Bowl safety Ken Hamlin.
"I don't really care too much about the depth chart right now, but it's awesome playing with the first defense," said Zbikowski a former third-round draft pick. "It's just fun to play. You can really rely on every one of these guys."
This year, there's something different about the former Notre Dame standout and heavyweight boxer from Chicago.
There's less of him.
Zbikowski has worked out and followed a strict diet to get down to roughly 200 pounds.
"I did a lot of plyometrics and boxing for conditioning," Zbikowski said. "It leans you down a bit. I've always been fast. Now, I feel like I've got that extra spring in my legs. The more I condition, the better I feel."
With the upgraded conditioning, Zbikowski is able to sprint much faster and is making more plays on the ball.
"I'm at like 200 pounds and I feel very good there," Zbikowski said. "As a rookie, I was about 215 and that was too much."
Now, it doesn't take him as long as it did in the past to close on a wide receiver or tight end. When he arrived in Baltimore, Zbikowski was stereotyped as more of an in-the-box enforcer type who would primarily play special teams.
Zbikowski, 25, seems to be evolving, though, into a rangier centerfielder type.
"Zibby is playing very fast," Harbaugh said. "He's really covering ground. He looks really quick."
Last season, Zbikowski started a career-high four games with Reed out. He was productive, intercepting two passes and recording 29 tackles.
With Reed out, Zbikowski knows that people around the NFL will underrate him and possible test him out.
"Yeah, they do sleep on me, but I've allowed them to," Zbikowski said. "I've been what I consider to be fat and out of shape before. Not really, but now I'm where I need to be. That's the process of being a professional. I think I've matured a little and adjusted all my weaknesses and am making them my strengths."