ENGLEWOOD, Colo. -- It’s not as though the Denver Broncos haven’t tried to handle what has been the biggest item on each of their past two offseason to-do lists.

They’ve used draft picks and written checks in free agency to make an offensive line that works the way they’d like it to. Yet despite all the victories along the way, including one in Super Bowl 50, the past two seasons they’ve said basically the same thing about protecting their quarterbacks better and making more room in the run game.

“I’m concerned in the consistency in what we’re doing," is how coach Gary Kubiak has put it. “...We have to be better in a lot of areas, but that’s certainly one of those areas, and we need it to be better quick."

The Broncos (7-4) are in the thick of a playoff race and sit in third place in the AFC West with five games remaining in the regular season. Quarterback Trevor Siemian has been battered, suffering shoulder and foot injuries already this season, and has been sacked 13 times in the past three games alone.

The Broncos' cherished run game, the same scheme that has churned out piles of 1,000-yard rushers through the years, is 19th in the league in rushing yards per game, and tied for 28th in average yards per attempt. The team has had one 100-yard rushing outing by a running back: C.J. Anderson in Week 7.

And as the Broncos approach a Week 13 game at Jacksonville, they’re still searching for the right combination. The Broncos used both Ty Sambrailo and Donald Stephenson at right tackle in Sunday’s loss to the Kansas City Chiefs, and Kubiak has said he would use both again moving forward; Stephenson is expected to start against the Jaguars.

Stephenson was benched in favor of Sambrailo last month but then replaced Sambrailo in Week 12 when Sambrailo struggled.

“I think [Stephenson] did respond," Broncos offensive coordinator Rick Dennison said. “I think when he went in the game, he did some good things. He had some flaws, we all did, coaches included. He did some good things and corrected some things. Obviously, we need to keep taking steps forward and keep getting better. This time of year is obviously the crunch time.’’

But it is a migraine-inducing riddle that's almost two full calendar years old, despite the use of eight draft picks since 2011 -- five in the past three drafts -- on offensive linemen. Of those eight, center Matt Paradis (sixth round, 2014), guard Max Garcia (fourth round, 2015) and guard Michael Schofield (third round, 2014) will start against the Jaguars.

The two tackle spots are expected to once again be Stephenson and left tackle Russell Okung. The Broncos signed them in free agency in the makeover that was supposed to repair the similar problems they had up front in 2015.

Sambrailo was a second-round pick in 2015 who has suffered serious shoulder and elbow injuries; rookie guard Connor McGovern, a fifth-round pick, hasn't played this season. So a team that has not used a first-round pick on an offensive lineman since selecting Ryan Clady in the first round of the 2008 draft will have to take a long look in the coming months at using its most premium selections on this unit.

Somewhat lost in all of this is the impact of Anderson’s season-ending knee injury, suffered in the Broncos’ victory over the Texans. In the seven games before he left the lineup, with the same cast on the offensive line, the Broncos averaged 4.1 yards per carry.

In the four games since Anderson went to injured reserve, the Broncos have averaged 2.8 yards per carry, again with the same groupings on the offensive line.

In the seven games Anderson played, the Broncos saw 31 rushes go for no gain or negative yards, an average of 4.4 per game that was too high for Kubiak’s liking. In the four games since Anderson’s injury, it's gotten worse: They’ve had 22 such rushing attempts, or 5.5 per game.

“We have to be better there," Kubiak said. "We have to find a way."

But solutions for the rushing issues will have to be found with the players already on hand. In the backfield, that will largely fall to rookie Devontae Booker and Kapri Bibbs. When the Broncos have run the ball effectively, it’s been far more difficult for opponents to pressure Siemian.

“The coaches have been letting us know what we need to do," Booker said. “...We talk about everything, every day. I think I’m getting better and want to make the plays we need to make. These are all important games."