RENTON — The Seahawks spent training camp with essentially the same starting five on their offensive line.

It was a group of five that included four returning starters or co-starters from the season before that made up what the Seahawks felt could give them as sturdy of an offensive line as they’d had in years.

“It’s come together quite well for us,” coach Pete Carroll said following the preseason of a group that consisted of second-year players Charles Cross and Abraham Lucas at left and right tackles, Damien Lewis and Phil Haynes at left and right guards, and Evan Brown at center.

“It’s been really steady and solid. … It’s been a very good camp for the O-line. They’ve done really well, and the consistency has been great.”

Once the regular season began, that consistency lasted four plays, which is when Cross departed the opening-day 30-13 loss to the Rams with a toe injury.

And at halftime, Lucas left with a sore knee.

That started a merry-go-round on the offensive line in which Seattle has started 10 different players, with at least two different players starting at least one game at each of the five spots, and with the Seahawks starting eight different offensive line combinations overall.

That’s in stark contrast to last season when the Seahawks were able to go with their preferred starting five 14 times and started just four different offensive line combinations.

The hope is that with Lucas appearing on his way back that the Seahawks may be able to start Thursday night at Dallas with their preferred five for the first time since that Rams game — or, at least, go with that five at some point along the way.

“I can’t even remember that far ago,” offensive line coach Andy Dickerson said with a laugh this week when asked about that prospect.

But this being the way things have gone with the Seahawks up front this year, just as Lucas may make it back there is suddenly a question mark hovering over Haynes, who did not practice Monday and Tuesday with a toe injury.

Because the Seahawks did not have to release a game status report until Wednesday, Carroll was intentionally as vague as possible about injuries when he met with the media on Tuesday for the last time before Thursday night’s kickoff.

“We’ll see,” Carroll said. “I don’t have to tell you so I’m not telling you.”

Carroll was a little more open about the status of Lucas, who has not played since the first half of the Rams game. Lucas remained on injured reserve as of Wednesday afternoon but returned to practice on Nov. 15, opening a 21-day window where he can practice before he has to either go on the 53-man roster or revert to IR.

Lucas practiced fully on Tuesday, and afterward, Carroll sounded optimistic he could play against Dallas.

“Abe had a good week,” Carroll said, saying the team is “counting on” him being able “to contribute. … Everything is kind of on schedule like we kind of planned it out quite some time ago, aiming for this week, and he did his part.”

Lucas wasnt listed on the team’s injury report Wednesday.

Jason Peters has been starting at RT with Lucas on the mend, and it’s unclear if Lucas would start or the two would rotate.

But if Lucas does return, maybe Seattle’s opening day will play together at some point Thursday.

Dickerson said this week that having to work with so many different line combinations has been a challenge but also it’s simply part of the job.

“How many times does an offensive line make it all the way through?” he said. “It’s very rare. Very rare. It’s part of the game. It’s a physical game, and injuries happen. Next man up is a cliché but that’s what you have to do. And nobody cares. The performance is the performance, and you try to get everybody ready.”

Still, in all of the talk this week of the offense lacking an identity in going its last 20 possessions without a touchdown, the impact of a continually shuffling offensive line can’t be ignored.

“It starts up front, as always,” quarterback Geno Smith said this week when asked what the offense can do to find its identity. “It starts with our run game. It starts with the discipline without the penalties, eliminating the penalties and going out and playing clean football. But it always starts up front.”

And the issues up front are undoubtedly part of why Seattle’s running game has struggled to match the effectiveness of last year. Seattle ranked just 18th in total rushing yards last season but was seventh in yards per carry — which coaches would argue is far more indicative of the effectiveness of the running game — at 4.8.

That number for this year is now down to 4.1, 21st in the NFL.

Seattle last year averaged 119.2 yards per game but has matched or bettered that total just three times this year — and only once since Week 4, and then doing so just barely, with 120 yards against Washington. For the season, Seattle is averaging 95.8 yards per game, 26th in the NFL.

In its losses to the Ravens, the Rams and the 49ers over the last four weeks, Seattle was held to 28, 68 and 88 yards, and per carry averages of 1.9, 3.2 and 4.2, respectively.

That Kenneth Walker III hasn’t played since the first series against the Rams surely is a factor.

But those struggles to establish a consistent running game have undoubtedly also played into why Seattle simply hasn’t run it as much as expected, with a 61-to-39 pass-to-run ratio, the sixth-lowest ratio in the NFL as of this week.

Why do more of something you’re not doing as well as you’d hoped?

Carroll repeated again this week that he’d like to balance out the pass-run numbers a bit more. He noted Seattle wanted to do that against the 49ers.

But as the Seahawks fell behind 24-3 at halftime, they had to resort to the pass more. Of 18 plays Seattle ran in the first half against the 49ers, just three were designed runs to a running back, with Zach Charbonnet picking up 7 yards on those carries.

“The first half, we had 16 plays [not including two sacks],” Carroll said. “It was five runs [including a reverse to receiver Dee Eskridge and a Smith scramble] and 11 passes. That’s not the balance that we want. We have to make first downs. We have to make first downs so that you get your chances. It’s a bad reoccurring theme, but I’ve got to get it right.”

What would help is a fully functioning opening-day starting five up front.

Dickerson said getting the in-game communication to be seamless is maybe the biggest challenge of working with so many different alignments.

“It’s all a challenge,” he said. “But the starting point is communication because if we are on the same page and everybody is targeted right and everybody is seeing the same things and anticipating the same things then I will feel confidence we can get all the things done that we need to. But that staring point and then the working together, the continuity, always helps. But at the end of the day, it’s still football and you’ve got to play with good technique and great eyes and get the job done.”