ENGLEWOOD, Colo. -- The Denver Broncos opened 2021 training camp July 27 at UC Health Training Center. Here's a closer look at a few storylines:

Who's the quarterback: Drew Lock or Teddy Bridgewater?

After an offseason when the Broncos had a leading role on every spin of the league's quarterback rumor mill -- from Deshaun Watson to Aaron Rodgers to Justin Fields -- Denver approaches training camp with the same quarterback depth chart it had in late April.

Drew Lock and Teddy Bridgewater will battle for the starting job with Brett Rypien hoping to get enough reps in practice and the preseason to convince the Broncos to keep him.

Lock and Bridgewater will have an old-school, throw-by-throw evaluation from the coaches as well as one from a social media army that follows the team. Whichever quarterback fixes the biggest item on his to-do list the quickest likely wins the job.

For Lock, it's maintaining his willingness to make the tough throw, but eliminating mistakes into coverage that keep happening. You simply can't say you're playing with swagger when you're tied for the league lead in interceptions and last in completion percentage.

For Bridgewater, it's maintaining his reliability, but not passing up opportunities down the field. He must make the kinds of throws that actually win games, something the game video showed he often did last season in Carolina.

Can this defense really be like 2015?

First-year general manager George Paton opened the team's checkbook to build a defense with the same framework as the "No Fly Zone" unit that led the Broncos to a win in Super Bowl 50 following the 2015 season. The team's two biggest signings outside of the organization were cornerbacks Ronald Darby and Kyle Fuller.

The Broncos also used their first-round pick on cornerback Pat Surtain II and signed safety Justin Simmons to a four-year, $61 million deal. It's clear in a division where Patrick Mahomes is king, the Broncos want to cover and cover well.

They now have the cornerbacks to play how coach Vic Fangio wants to play. And for a team that hasn't averaged more than 23 points per game on offense since 2014 and has only averaged more than 21 points per game in one season over the past six, defense may still have to power the success given the quarterback competition that's under way.

But if Fuller, Darby, Surtain and Bryce Callahan can all be in uniform for 17 games, the Broncos' record should reflect that.

What will Von Miller's rebound from 2020 look like and how does Bradley Chubb fit in?

When the Broncos selected Bradley Chubb with the fifth pick of the 2018 draft they thought the team would pile up sacks as Von Miller and Chubb terrorized quarterbacks for years to come. And in 2018 the two did combine for 26.5 sacks.

But due to injuries over the past two seasons the pair hasn't even played in the same game since Week 4 of the 2019 season when Chubb tore an ACL against the Jacksonville Jaguars. Miller then missed last season with an ankle tendon injury he suffered just days before the regular-season opener.

Miller has attacked the offseason and wants to prove he can be the dominant game-altering player he has been during his career. The Broncos believe he is poised for a big year. Chubb had ankle surgery this offseason, but he is expected to be full-go by the start of the regular season.

Injuries have derailed the Broncos' defensive plans in recent seasons, especially in 2020, but a healthy Miller and Chubb should have enough time to get to the quarterback with a reworked secondary behind them.

What's it really going to take to end playoff drought?

Some reasonable good health for one. The Broncos had a high-profile list of players on injured reserve last season, led by Miller, and never recovered from it, extending their playoff drought to five seasons.

But they also need a September that isn't awful -- they're 0-7 in September the past two seasons combined -- and they need an offense that doesn't consistently give the ball away in its own territory or can't finish even an average amount of drives with touchdowns.

Last season the Broncos were 27th in the league in the red zone and 28th in scoring overall -- that's not the company a playoff team keeps.