The Broncos' 2020 season is almost here, and as training camp approaches, we're taking a look at each of the Broncos' position groups. In this set of previews, we'll take a deep dive into what we know about the given position group and what we still need to learn. We'll also identify a player to watch and choose a battle that bears watching. At the end of the series, we'll provide an overarching look at the best training camp battles and which players have the most to prove.

We continue the series with a look at the safety position.

What we know:

Justin Simmons enjoyed his best season as a young pro as he broke out in his first year in Head Coach Vic Fangio's system. The Broncos' prized free safety tallied four interceptions and 15 passes defensed as he guided the Broncos' safety unit and earned second-team All-Pro honors. Though he was snubbed for the Pro Bowl, Simmons finished the year having played every snap for the second consecutive season. After an offseason of contract negotiations, Simmons will return to the Broncos in 2020 and play out the year on the franchise tag.

And while Simmons serves as the Broncos' rangy center fielder, they also return their hard-hitting playmaker in Kareem Jackson. The 11th-year pro returns for his second season in Denver after earning Pro Bowl alternate status in 2019. When on the field — Jackson battled a hamstring injury early in the year and was suspended for the final two games of the season — he made major contributions to the Broncos' run defense and their physical nature. Jackson's hit on Austin Ekeler to force a goal-line fumble and his open-field shot on DeAndre Hopkins stand out as two of the Broncos' biggest plays of the season.

The position group will feature some new faces, too, after Will Parks departed for Philadelphia in free agency. Trey Marshall is the most-experienced player to return, as he appeared in 16 games last season and started the final two contests in place of Jackson.

Former undrafted cornerback Alijah Holder will move to safety to compete for a role, and undrafted rookie Douglas Coleman III will also aim to earn the job after a successful final season at Texas Tech. First-year players P.J. Locke and Kahani Smith will also compete for a roster spot.

What we need to learn:

Truly, there's not much we need to find out about the safety group. Simmons and Jackson should be even more comfortable in their second season together in Fangio's defense, and the duo should be one of the league's best. 

Given the reported cancellation of the preseason, Marshall should have a strong edge to earn one of the two likely reserve spots at the position. 

We don't know much, though, about how Holder will look in the back end of the defense or how Coleman's turnover-minded game translates to the NFL.

Simmons' health over the last two seasons has been a luxury, but the Broncos must find capable backups in case either he or Jackson misses time.

Player to watch:

Kareem Jackson

We're curious to see if Simmons continues to progress in Fangio's defense, but Jackson may be the key in the secondary. The now-32-year-old player showed few signs of aging in 2019 as he record a pair of interceptions, 10 passes defenses, a forced fumble, 71 tackles and a fumble return for a touchdown. If Jackson can continue to play with the same energy and intensity and Simmons takes a step forward, the Broncos may present the best safety duo in the league. 

And while some players will suffer from the limited offseason, it's possible Jackson may benefit from the limited reps and lack of preseason games. 

Battle to watch:

As we mentioned above, Trey Marshall seemingly has a solid hold on the third safety spot. Holder and Coleman seem to be the most likely competitors for the final spot on the roster. The Broncos moved Holder to safety late in the preseason, and he intercepted a pass in the preseason finale. Holder then spent the season on the Broncos' practice squad. Douglas, meanwhile, ranked first in the nation in interceptions among players at Power 5 schools after switching to safety ahead of his final season in Lubbock. Don't rule out Locke or Smith pushing for reps, as this truly feels like an undecided battle. With the relative youth among the Broncos' reserves, it's also possible the Broncos could try to pick up a player off waivers after roster cutdowns.