Second look at Broncos' preseason opener

After further review ...

The Denver Broncos' preseason opener Thursday night was formally filed away as a 10-6 victory, but as expected there are some loose ends that will need attention as the team continues to plow through August.

• A battered offensive line could force the Broncos to go to a far more quick-hitting passing attack in the immediate future, with far more three- and five-step drops to get the ball out faster. Especially if the Broncos continue to open the formation in a three-wide look as they did in the brief time the starters were in the game at San Francisco.

They signed Wes Welker, so certainly the three-wide receiver package could be their base offensive formation, but it's far dicier to play it if they can't keep opposing rushers off Peyton Manning's doorstep.

Left tackle Ryan Clady, working his way back from offseason shoulder surgery, is still expected to be ready for the regular-season opener against Baltimore. His return will certainly help. And while right tackle Orlando Franklin's hip injury kept him out of some practice this past week, he was able to work through seven plays with the starters Thursday against the 49ers.

But the 49ers' defense -- the first through third units -- created pressure on the Broncos' passers throughout the game, particularly in the middle of the formation. Brock Osweiler showed plenty of progress and athleticism, but he was forced off schedule far too often to find any real offensive continuity. He was sacked three times in just over two quarters of work.

• With a limited game plan, the Broncos ended their first eight possessions with a punt and on the ninth surrendered the ball when they couldn't convert a fourth-and-1 to continue what had been their best offering of the game -- a 91-yard drive. They had seven possessions in the first three quarters that went for 25 yards or fewer.

Their top three backs -- Ronnie Hillman, Montee Ball and Knowshon Moreno -- averaged a combined 2.9 yards per carry against largely no-frills defensive fronts. That's another indicator the Broncos are a work in progress as they try to expand the scope of their run game.

Last season, Denver was not all that effective, or willing, to stress defenses outside the hashmarks in the run game. At least part of the reason the Broncos brought back Alex Gibbs to the coaching staff was to improve that piece of the offensive puzzle.

Until the Broncos show a little more in that regard, teams are going to pack the middle of the field on them.

• Second-year cornerback Omar Bolden made the best play in coverage during a stadium scrimmage last weekend, and he was active against the 49ers. When the team is at full strength -- Dominique Rodgers-Cromartie is currently sidelined with an ankle injury -- Bolden hasn't yet cracked the dime package, but he's showing progress.

Bolden missed his final season at Arizona State with a torn ACL, so the Broncos thought it might be late in his rookie season in 2012 and into this year before they saw everything he has to offer. Bolden plays with confidence and could give defensive coordinator Jack Del Rio far more options in some of the team's specialty looks, including the seven-defensive back offering Del Rio used plenty last season.

• The Broncos will be pleased they forced a field goal from the 49ers' starters to open the game. Still, the first-team defense was a bit wobbly at times. San Francisco held the ball for more than seven minutes on that opening possession against a defense that was fully staffed for the most part.

Rodgers-Cromartie was the only starter who did not play, and his replacement, Chris Harris, was the starter at right cornerback last season.

But the 49ers consistently moved the line of scrimmage in largely heavy multiple-tight end or multiple-back formations, and the Broncos had some difficulty reining in Colin Kaepernick in his cameo.

After Kaepernick exited, the Broncos held the 49ers to six possessions without a first down over the remainder of the game. And it was simply the first preseason outing. Still, if the Broncos hope to push deep into the postseason when things get started for real, they are going to need to be able to muscle up on defense out of their base formation better than they did Thursday night.