ENGLEWOOD, Colo. (AP) One thing that Peyton Manning, Brock Osweiler, Trevor Siemian, Mark Sanchez and Paxton Lynch all quickly learned in Denver was that nothing comes easy against the Broncos' "No Fly Zone" secondary at practice.
It's something opposing quarterbacks discover on game day.
Aqib Talib and T.J. Ward are no longer here, but Chris Harris Jr., Darian Stewart, Justin Simmons and Bradley Roby remain.
On Tuesday, Case Keenum got his first taste of that stellar defensive backfield that still uses the moniker following Ward's dismissal last year and Talib's trade to the Rams this offseason.
When asked what it was like facing the merry band of pass snatchers in his first 11-on-11 drills since signing with Denver two months ago, Keenum feigned ignorance of the stellar secondary's sobriquet.
"Is that their nickname? Is that what they're called?" Keenum asked. "Is it? OK. Well, it's good to know. Yeah, they're talented. They're a talented squad. And I think ... going against good, it makes you better."
When the full pads come out and summer comes around, Keenum will get a pass from the Broncos' bevy of pass rushers, donning a different color jersey to signal he's off-limits to the likes of Von Miller, Shane Ray, Bradley Chubb and Shaq Barrett.
He won't get any favors, though, from the No Fly Zone, which has both perturbed and polished Broncos QBs and offensive coordinators since the group formed during Manning's tenure and helped them win a Super Bowl.
Facing these defensive backs will surely chagrin and sharpen Keenum, too.
"I think competition not only within positions and yourself, but against the defense, coming out here and competing here every day against the No ... Fly ... Zone ... it's going to be really good," Keenum said, slowing down to pronounce the nickname right.
"I'm excited. It's fun competition. Those guys are really good."
Keenum signed a two-year, $36 million free agent deal in Denver after leading the Minnesota Vikings to the NFC championship game.
The Broncos, who held QB competitions each of the first two seasons following Manning's retirement, quickly declared Keenum their starter and said Lynch and Chad Kelly would vie for the backup job. This week they added former Colorado State QB Nick Stevens to the mix.
This marks the first time Keenum has entered an offseason program as the established starter since joining the league as an undrafted free agent out of the University of Houston in 2012.
"It's been fun to watch," coach Vance Joseph said. "It's good for our football team. It's good for our coaches."
"Yeah, it feels different," Keenum said. "It feels good. I like it. I like competing and I like knowing my place and knowing my role. There's some comfort to that and I think that puts different things at ease and lets you go out there and play, lets you cut it loose. It's nice."
Keenum is 20-18 in six seasons with the Vikings, Rams and Texans and is coming off his best season yet, one in which he went 11-3 as Minnesota's starter after a knee injury sent Sam Bradford to the sideline.
He checked in Monday night at No. 51 in the NFL's Top 100 43 spots better than Kirk Cousins, his successor in Minneapolis who signed a groundbreaking, fully guaranteed, three-year, $84 million deal this spring.
"Yeah, that was cool," Keenum said of his ranking. "It's something that's voted on by our peers, so it definitely means a lot to me. I'm looking to build on that and move forward with these guys here."
Notes: Five players were sidelined at the start of OTAs: T Jared Veldheer (foot), G Ron Leary (knee), TE Troy Fumagalli (sports hernia), WR Jordan Taylor (hips) and DT Clinton McDonald (shoulder). ... With Veldheer out, Billy Turner lined up at right tackle. T Menelik Watson moved inside to RG, sharing snaps with Connor McGovern. ... RB De'Angelo Henderson practiced a week after he was hit by a drunken driver.
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