Editor’s Note: Fourth of an eight-part series breaking down the Broncos’ roster as they reboot under new head coach Vance Joseph. Friday: Offensive line. Up next: Defensive line.

Sigh. It’s time to discuss the spot on the Broncos’ roster that needs the most work for the team to get back to championship contention.

The Broncos headed into the 2016 offseason with fixing their offensive line as a top priority. They went bargain shopping for Russell Okung and Donald Stephenson to secure the edges and replaced Louis Vasquez and Evan Mathis with younger talent at guard.

They struck out swinging.

The Broncos 2016 offensive line was worse than the 2015 bunch. This 2017 offensive line has to be more physical, cohesive and more disciplined than in each of the past two seasons.

Broncos general manager John Elway has the dubious task of cleaning up this mess.

Denver’s first big decisions will come with Okung and Stephenson, who failed to meet expectations. The Broncos must make decisions on retaining none, one or both by early-to-mid March.

Okung has a $1 million team option due on March 9, which, if picked up, would kick in a four-year, $48 million contract with $21 million guaranteed. It’s unlikely the Broncos will pick up that option. They owe Okung nothing if he’s released. The two sides could restructure.

Stephenson has a smaller chance to remain a Broncos starter. He played poorly at right tackle and was benched multiple times for Ty Sambrailo. Stephenson would have a $5 million cap hit in 2017, but the Broncos could save $3 million in cap space if they release him before March 13 when his $4 million 2017 base salary is guaranteed.

A new offensive scheme will play a role in how the 2017 offensive line is built. Broncos offensive line coach Jeff Davidson traditionally runs a power blocking scheme rather than the zone scheme Gary Kubiak used. Offensive coordinator Mike McCoy’s flexibility means it will likely be a mixture of power and zone.

More strength up front would help on short yardage situations, a weakness last season.

The Broncos have only one true building block on the offensive line in center Matt Paradis. He was a Pro Bowl alternate in 2016. Paradis was the offensive line’s leader, and played every offensive snap over the past two seasons.

But even Paradis, who turns 28 in October, has question marks. He had surgery on his right hip Jan. 10, and he’s expected to have surgery on his left hip within the next week. Paradis expects to be fully recovered by the start of the 2017 season, but the surgeries are reason for concern.

Neither Max Garcia nor Michael Schofield should have solidified starting spots going into next season. Both were inconsistent and need to improve to keep their roles. Garcia, a 2015 fourth-round pick, has the best chance of the two to remain a starter.

Sambrailo, the Broncos’ 2015 second-round pick, must also show significant improvement. He should spend a lot of time in the weight room getting stronger, preparing for a switch to guard and still his roster spot might not be safe.

Guard Connor McGovern, who didn’t play his rookie year, could contribute in 2017 under a power scheme.

Several players the Broncos might consider in free agency are Baltimore Ravens tackle Ricky Wagner, Dallas Cowboys guard Ronald Leary, Cincinnati Bengals tackle Andrew Whitworth and guard Kevin Zeitler, and Detroit Lions tackle Riley Reiff and guard Larry Warford. Some may re-sign with their current teams, but the Broncos should target a couple of them.

It’s unwise to count on any rookie offensive linemen the Broncos could draft to be an immediate, consistent starter. Still, they will look to the draft for depth and for the long run.

Alabama’s Cam Robinson, Utah’s Garett Boles, Wisconsin’s Ryan Ramcyzk, Western Kentucky’s Forrest Lamp, Troy’s Antonio Garcia, Temple’s Dion Dawkins and Western Michigan’s Taylor Moton are draft options for Denver in the first three rounds.

The Broncos are preparing for an overhaul, but it’s tough to replace an entire offensive line in one offseason.