SANTA CLARA >> As the 49ers’ season comes to a close amid an avalanche of missed games, Dominick Puni remembers the one that got away.

The one snap, that is.

It happened with 9:28 to play in the first quarter of an eventual 30-13 win over the New England Patriots in Week 4. Puni took a blow to the stomach on a 1-yard run by Jordan Mason.

“I had one snap where I got the wind knocked out of me and they told me to stay down, so I missed one snap this year,” Puni said Saturday as the 49ers (6-9) concluded preparations to host the Detroit Lions (13-2).

Puni, a rookie third-round draft pick out of Kansas, will be in his usual spot as the starting right guard Monday night as the 49ers close out their home schedule. Jake Brendel will be the center. The rest of the offensive line will be determined at some point before kickoff.

Spencer Burford, the third 49ers left tackle, was declared out with a calf injury, along with left guard Aaron Banks (knee), linebacker Dre Greenlaw (calf) and defensive end Robert Beal Jr. (ankle). Right tackle Colton McKivitz is listed as questionable but didn’t practice all week with a knee injury. Also questionable were safety Ji’Ayir Brown (ankle), linebacker Tatum Bethune (knee) and cornerback Charvarius Ward (personal matter).

Banks is expected to be the 14th player to go on injured reserve, although Bethune is eligible to be activated from I.R.

If McKivitz doesn’t play, the 49ers starting line could consist of newcomer Charlie Heck at left tackle, Nick Zakelj at left guard, Brendel at center, Puni at right guard and Austen Pleasants, a recent practice-squad promotion who signed on Dec. 17, at right tackle.

Coach Kyle Shanahan characterized the challenge of playing mix-and-match this way.

“You try to keep it simple for them, try to categorize stuff in groups, and the guys next to them just, they try to communicate as much as possible and you try to help him out,” Shanahan said.

Puni, who has established himself as a foundation piece going forward, finds himself possibly being in the unusual position of dispensing advice and wisdom at age 24.

“With these tackles, whoever is going to play next to you, you’ve got to tell them some things,” Puni said. “If you just get here, you’re not going to know all the tricks of the offense. Other than that, I’m just going to try and control my one-eleventh and do my job. It is exciting though.”

Puni’s 938 snaps are the most on the team — two more than McKivitz and three more than Brendel. It’s remarkable when you consider Puni had to nearly avert his eyes during some recent film study of his own practices and game tape when he first arrived as the 86th overall pick of the draft.

“I went back to rookie minicamp, the fall camp, the first three training camp practices, just to see how bad I was when I first got here compared to now,” Puni said. “It’s like a night-and- day difference. When you get here, you don’t know the offense, you don’t know the technique.

Yet by the third training camp practice, Puni (6-foot-5, 315 pounds) was the starter. He’s never relinquished the position, and health permitting, isn’t likely to be out of the lineup for years.

“I got a lot of reps with the (first team) and that’s the only reason I was able to do so well early in the year,” Puni said.

Puni credits linemates such as McKivitz, Brendel, Banks, Burford and Trent Williams as well as line coach Chris Foerster for helping to bring him along, but it’s clear he’s been a quick learner who wears durability as a badge of honor.

Puni’s outlook is appealingly old school while the outside world fixates on who should and shouldn’t play regardless of injury on teams out of the playoffs.

“You don’t ever want to miss a snap,” Puni said. “If you can be out there, you’ve got to play. The last thing I want to do is bring a backup guy in who has been sitting on the sidelines and now he’s got to go in, and I don’t think that’s fair. If I can play, I’m going to play.”

GUERENDO GOOD TO GO >> Running back Isaac Guerendo (foot, hamstring) was a full participant in practice and wasn’t given a status after missing the Miami game, meaning the 49ers should get another look at their fourth-round draft pick as a lead back.

“It was good to have him back,” Shanahan said. “We had a full-speed practice (Friday) and he looked good. So no holdbacks. He’s good to go.”

Also good to go is fullback Kyle Juszczyk, who missed the two previous days with an illness.

Ward, who lost his 23-month old daughter in October, is awaiting the birth of his son and currently away from the team.