ALLEN PARK >> It’s often said that the Lions’ offensive success has much to do with rostering one of the best offensive lines in the league.

But as a unit, Detroit’s offensive line has seen some drop-off compared to the production of years past — particularly in pass protection — and in recent games, which has really hurt the run game.

Lions offensive coordinator Ben Johnson said the offensive line play has been “up and down.”

“It hasn’t been consistent throughout the year,” Johnson said. “We’ve had glimpses of being a dominant unit and then there are other times, like last week (against Buffalo), that we just weren’t ourselves.”

Running backs Jahmyr Gibbs and David Montgomery ran the ball a combined 13 times against the Bills, totaling just 35 yards rushing for an average of 2.7 yards per carry. It wasn’t a whole lot better the previous week against the Green Bay Packers, when Detroit picked up 94 yards on 29 carries from Montgomery and Gibbs, for an average of 3.2 yards per carry.

Johnson said there wasn’t anything in particular that Buffalo was doing to prevent Detroit’s run success.

“I think there were only 13 runs in that game, and we only had four efficient ones. There were things that were popping. It was less what Buffalo was doing to us; they really didn’t do a whole lot that we didn’t expect on the run plays,” Johnson said. “It was more self-inflicted and things that we feel like we can take care of each and every week and we’ll be just fine moving forward.”

The Lions’ pass protection held up well against Buffalo, considering that quarterback Jared Goff threw the ball 59 times. Generally speaking, however, they’ve had better seasons.

Goff has been pressured on 34.3% of snaps this season, per Next Gen Stats, which ranks 20th among qualified quarterbacks, and his average time to throw (2.8 seconds) ranks 17th.

NFL data journalist Ben Baldwin’s pass protection composite ratings — which combines data from Pro Football Focus, Sports Info Solutions and ESPN to give a complete look at who’s best at protecting the quarterback — has the Lions ranked 10th in that category. That’s a slight uptick from earlier this month when they ranked 15th after Week 13, just one spot above the oft-criticized unit of the Chicago Bears.

“I will say, in regards to last game, the protection was — for throwing it 59 times — pretty good,” Johnson said. “We felt like our guys really answered the bell in that regard. It’s not necessarily always rushing statistics, it’s not always sacks. It’s looking at everybody individually...”

and we’ve had some pretty consistent performances across the board. It’s just collectively, it hasn’t come together for an entire 60 minutes in a while.”

The Lions have a chance to get things back on track this weekend in the great outdoors at Chicago’s Soldier Field, though they won’t have Montgomery, who’s dealing with a knee injury suffered against Buffalo.

Against the Bears in Week 13, Detroit lit it up in the run game. Montgomery rushed for 88 yards on 21 carries (4.2 average) while Gibbs exploded for 87 yards on nine runs (9.7 average).

In their last two games, the Bears have given up 245 total rushing yards on 63 carries.

“We had some success against this team, Chicago, the last time that we played them, particularly in the first half running the football, so hopefully we can build on that,” Johnson said. “They certainly have had some struggles over the last couple of weeks just limiting the number of points, but we know they’re going to come out and they’re going to come out firing. It’ll be a good challenge.”

Gibbs is confident Detroit’s run game will get back to the standard they’ve set over the last couple of years.

“The whole offense wants to get back to that standard,” Gibbs said. “That’s what we leaned on the most, so just getting the details right and getting back to where we left off, we really want to do that.”