Quarterback decision leads off Broncos' to-do list in training camp

ENGLEWOOD, Colo. -- The Denver Broncos formally get down to training camp business Thursday morning, and the defending Super Bowl champions have some significant questions to answer if they are to return to the postseason.

The five biggest are:

Who’s the quarterback?

The Broncos open camp with coach Gary Kubiak having thrown the competition for the starting quarterback job wide open. Mark Sanchez, Trevor Siemian and rookie Paxton Lynch will get an equal amount of work to start camp, with Sanchez getting the first crack to run the first-team offense in practice.

Kubiak not only wants to see the quarterbacks handle their football business -- making the right throws to the right people as well as limiting mistakes -- but he wants to see how a guy “handles the team," in being a leader and stepping forward with a little swag.

The Broncos need one of the three quarterbacks to be a clear winner to limit the impact a decision might have in the locker room this season.

Will the offense be more grounded?

Peyton Manning's tenure in Denver was epic. At its best, the offense was a high-flying touchdown factory, with Manning at the center of it all.

Change is on the way with Manning out of the mix. The Broncos will add a fullback to the offense, they’ve beefed up the offensive line and Kubiak has promised a little more dedication to the running game -- which had 25 or fewer carries in 10 regular-season games. They want the play-action back in the passing game.

They were 17th in the league last season in rushing yards and rushing attempts. They believe they need to better help the new quarterback, control tempo and, as Kubiak put it, "be more physical."

Can the defense repeat?

There is no question that the Broncos' defense powered the Super Bowl run. The book around the league is it will be difficult for the Broncos to play with that same edge that put them into the No. 1 spot of virtually any defensive category that mattered last season.

The Broncos need Von Miller to show his postseason form from the first week on. They'll also need the same selfless, hold-everybody-accountable approach that served them so well last season, because offenses have spent an offseason looking for their weak spots.

What are the other position battles to watch?

Beyond naming a quarterback, the Broncos have to find an inside linebacker to replace Danny Trevathan. Todd Davis has a slight lead over Corey Nelson to win the job as camp opens.

The Broncos also need running back C.J. Anderson, who has promised to be in the "best shape of my life" when camp opens, to be the go-to guy the Broncos hoped he could be when they matched an $18 million offer sheet from the Miami Dolphins to keep him.

Anderson has not had at least 180 carries or 850 rushing yards in any of his previous three seasons. The Broncos want -- and expect -- him to change that this season.

Where will the toughest roster decisions happen this time around?

There’s a crowd at running back with Anderson, Devontae Booker, Ronnie Hillman and Juwan Thompson all hoping to carve out some playing time. Booker, a rookie, is going to force his way on to the field in some fashion, so the Broncos could have a tough call in the making if they keep rookie fullback Andy Janovich, a sixth-round pick in this year's draft, as expected.

Things are also crowded on the defensive line with the additions of Jared Crick, Phil Taylor and rookie Adam Gotsis this offseason to a group that already included Vance Walker, Sylvester Williams and Derek Wolfe.

And the Broncos are on the hunt to fill some significant roles on special teams, where longtime punter Britton Colquitt's $4 million salary-cap figure could impact his place on the roster, especially since they selected punter Riley Dixon in the draft. The Broncos are also on the hunt for kickoff and punt returners.

The Broncos would rather not keep someone primarily as a returner, so the choices will most likely have to bring something to the table on either offense or defense. Special teams captain David Bruton Jr. departed in free agency, too, so the Broncos must find a replacement for one of their core special-teams players.