Replacing retired safety Brian Dawkins in the starting lineup is free agent Mike Adams alongside second-year pro Quinton Carter. And instead of Andre' Goodman playing opposite Champ Bailey at cornerback, it'll be Tracy Porter with fellow free agent Drayton Florence helping defend the spread offenses that are all the rage in the NFL these days.
"I miss the guys that were here, but the good thing is we replaced them with some really good players," Bailey said.
"We've got three great cover corners to work against," Manning said this week as the Broncos began their first full practices of the offseason. "... I mean, if you can't get better going against some of these top cover corners, then it's just not meant to be."
Bailey, who turns 34 next month, is coming off his 11th Pro Bowl, which extended his record for cornerbacks. Crashing the playoff party last season for the first time in six years and beating Pittsburgh in the first round just wasn't enough for him.
"People think we should walk around here with a smile on our face because we made the playoffs, we won a game. We came up short again," Bailey said back in January. "For me personally, I don't have a lot of time here. I don't know how much longer I'll play. It's one of those things, every year you miss it and you don't win it and here we go again, we've got to start all over again."
The Broncos made some enormous changes in the offseason, jettisoning Tim Tebow for Manning, the biggest free agent prize in NFL history, and bringing in former Jacksonville coach Jack Del Rio as defensive coordinator to replace Dennis Allen, who left after just one season to coach the Oakland Raiders.
"I'm just trying to soak up as much as I can on the field," Porter said. "Any question I think of on the field I run and ask him."
Porter said he's also picking Manning's brain to see what an elite quarterback looks for when deciphering defenses.
"Not yet. Coming close. Maybe a little bit down the line, but right now I'm just trying to grasp the defense and the playbook, he's trying to take control of that offense," Porter said. "So, I think once we get settled in, we'll have enough time to shoot that little joke in. But as of right now, we're both still learning."
"He's sharp, he knows his stuff and that's really what you want from your safeties, to know their stuff and to come out there and kind of get you lined up right," Bailey said. "I mean, I don't need it for the most part, but when I do, I want to be able to lean on somebody."
Adams is wearing No. 20, just as he did in Cleveland, in honor of Dawkins, whom he began to admire and emulate back at the University of Delaware a decade ago.
"I enjoyed watching him my whole career and hopefully I make him proud wearing that number," Adams said.
And a starting job.
"Coach (John) Fox told me that if I come here everyone is going to be competing; nobody in the secondary has a job except for Champ Bailey, which is obvious, and everyone else is out there competing and that is what we're going to do," Florence said. "All the good teams have competition at every position and that is how you build a successful team."
Notes: Fox invited the Air Force Thunderbirds squadron to practice Tuesday. Fox's ride-along was scrubbed Monday because of mechanical problems. ... Among Broncos coming back from injury who are participating in the organized team activities (OTAs) this week are RB Knowshon Moreno (knee), DT Kevin Vickerson (ankle), DBs Thompson (Achilles tendon) and Vaughn (ankle), RB Mario Fannin (knee) and WR Mark Dell (knee).
Follow AP Pro Football Writer Arnie Melendrez Stapleton on Twitter: http://twitter.com/arniestapleton