His legs were moving, but C.J. Anderson was running in place. The Broncos tailback bumped into trouble twice on Denver’s first drive Saturday night against the Los Angeles Rams and twice fell backward. His offensive line was leaning in the wrong direction.

“It’s a work in progress,” Broncos center Matt Paradis said.

Now that the Broncos finally, seemingly, have settled on a starting quarterback in Trevor Siemian, the next looming question might be even more important: Can he survive the first month?

The Broncos’ offensive line, a ragtag unit that got trampled on last season, is piecing together a new front five. The first team, for the most part, finally played together Saturday. The results were mixed.

Denver’s offense gained just 27 yards in the first quarter against the Rams’ first-team defense. The Broncos twice went three-and-out, with 7 total yards over six plays from scrimmage in their first two drives. All those plays were runs. Four of the six went for losses or no gain.

The Rams, a 7-9 team last season, pushed into Denver’s backfield on six tackles for lost yardage.

“We started slow,” Broncos coach Gary Kubiak said. “We were trying to run the ball, and we didn’t run the ball well. The first two games we went right down the field the first two drives. What I do is I build on the positives. That’s what we’ll continue to do.”

On the bright side for the Broncos, Siemian was touched only twice on hits from the Rams’ defense. He was never sacked. But the Broncos are walking a thin line up front, so to speak.

“We have a lot of work to do,” Broncos left tackle Russell Okung said. “We definitely have the talent up front. Guys have amazing skill sets. There’s time to bring it together.”

Okung, the Broncos’ most expensive offseason free-agent offensive signing at $5 million this year, finally saw sustained playing time with the first-team line. Okung and fellow free-agent addition Donald Stephenson at right tackle saw sparse field time in the first two preseason games. The Broncos were protecting them, just as a string of training camp injuries nicked their depth.

But with presumptive starting right guard Ty Sambrailo still sidelined with an elbow injury, the Broncos flashed their likely starting front five against the Rams, with Michael Schofield in for Sambrailo at right guard, Paradis at center and Max Garcia at left guard.

If nothing else, the Broncos gained some experience on the offensive line over a year ago. Evan Mathis left for the Arizona Cardinals, but Okung and Stephenson replaced him as veterans. Paradis, who played every offensive snap last season, returns as the anchor. Schofield, so maligned a year ago, has learned to play multiple positions.

“We have the potential to be the best offensive line in this league, undisputed,” Okung said Saturday night. “There’s a tenacity and physicality to our group. We have guys who can do everything, run block as well as pass block. And we have a balanced offense — that really plays to our group.”

The Broncos’ O-line, though, has a long way to go before even entering the conversation of best lines. They ranked near the bottom third in the NFL last season for sacks and quarterback hits. Siemian, who will throw his first NFL pass Sept. 8 in Denver’s opener against the Carolina Panthers, may have to play on his toes this season.

“There’s time to bring it together,” Okung said. “As long as we gain a blade of grass, we’re doing a good job there. Games are long. You can’t always win it early.”