John Lynch acknowledges there’s plenty of work to do as far as rebuilding the 49ers, but perhaps not as much as the team’s 2016 record suggests.

“We’ve got some strides to make on this roster, but I can also tell you (that) I don’t look up at the film we’ve been watching and see a 2-14 team,” the 49ers’ new general manager said on KNBR radio Wednesday. “I see some pieces that are hard to build, you know? A great example of that, I think, you look at our offensive line and our defensive line. I’m actually excited about those groups. And those groups are where, I believe, football games are won and lost. It starts there.”

The 49ers’ offensive line returns intact from 2016, which ought to provide some cohesion. The group also has been running many of the zone-blocking concepts new coacch Kyle Shanahan uses in his offense. Atlanta ranked fifth in rushing yards in 2016; the 49ers ranked fourth.

However, 337 yards of San Francisco’s rushing total came on quarterback scrambles from Colin Kaepernick over the last 11 games while the 49ers allowed the third-most sacks (47) in the league last season. Pro Football Focus rated the 49ers’ offensive line 28th of 32.

Perhaps the unit’s biggest issue is depth. Last season, right guard Zane Beadles turned out to be the team’s top backup at left tackle, right tackle and center, which is problematic if there are injuries at two or more spots.

The defensive line, meanwhile, was the front line of a unit that last year allowed more total yards, more rushing yards and more points than any other 49ers defense in the franchise’s 70-year history.

Lynch’s optimism likely revolves around the team’s most recent first-round picks, Arik Armstead and DeForest Buckner. Armstead, 23, played in spite of a shoulder injury for eight games before going on injured reserve. Buckner, meanwhile, was the team’s ironman in his first NFL season, playing more snaps than any other defender and leading the team in sacks (he tied with Ahmad Brooks with six) and quarterback pressures.