Offensive lineman Anthony Davis stunned the 49ers on Saturday when he pondered retiring again, only two days before he was to start at right guard in Monday night’s season opener, multiple sources told this newspaper.

Davis has not publicly commented on his intentions and he did not return a text message seeking comment. The 49ers, including coach Chip Kelly, have tried to convince Davis to keep playing, a league source indicated.

A high-ranking team official said he “honestly” did not know what Davis would do. Comcast SportsNet Bay Area’s Matt Maiocco reported that Davis was “leaning” toward resuming his playing career, and NinersNation.com’s Jennifer Chan said Davis’ “doubts” about converting to right guard had been eased after meeting with general manager Trent Baalke.

Davis did not practice Saturday “for non-injury-related” reasons, the 49ers said on their participation report, which also listed him as questionable (or 50/50) for the opener against the Los Angeles Rams at Levi’s Stadium.

A team spokesman would not confirm Davis’ status. Davis’ agent, Drew Rosenhaus, declined to go on the record regarding Davis when reached via e-mail.

Bleacher Report’s Jason Cole and ProFootballTalk.com both cited an anonymous source that Davis would not retire.

On July 30, Davis emerged from a 1 1/2-year hiatus to rejoin the 49ers in training camp, and although he wasn’t able to unseat Trent Brown and reclaim the starting right tackle job, Davis appeared willing to start at right guard. Davis also was set to be their swing tackle, or the backup to either Brown or left tackle Joe Staley.

Andrew Tiller, who broke into the starting lineup the second half of last season, is expected to start Monday night instead of Davis at right guard. Tiller was called up from the practice squad last November, starting four games at right guard before switching to left guard the final three games.

If Davis does retire, it would be a devastating blow and an ill-timed one for a 49ers franchise he mocked during his previous sabbatical.

During that hiatus — officially classified as a “retirement” by the 49ers in June 2015 — Davis occasionally took to Twitter and criticized the 49ers organization, general manager Trent Baalke and even left tackle Joe Staley. On April 1, when Davis tweeted he would be filing for reinstatement, he added: “Dealing with Trent is giving me a headache.”

Once he did report for camp, Davis said his social-media barbs toward Baalke and the 49ers were “me trying to manipulate emotions to get what I wanted, at that time.” Baalke’s response on July 31: “I’m hard to manipulate. … Everything is very positive at this point, and it’s about blending back in and going to work.”

Davis didn’t show any doubt about his ability to switch from right tackle to right guard last month when he embarked on the move, doing so in a joint practice at the Denver Broncos’ facility. He had been lining up primarily as the second-string right tackle, after debuting there on the third string once he reported to camp.

“I’m an athlete. I can play right tackle or anywhere on the line,” Davis said Aug. 18. “We want the best five (lineman) on the field and Trent (Brown) is not going to play guard. He’s a giant man. I knew I could adapt to guard. …I’ll be on the field sooner or later. I’m pretty good at football.”

Davis said he volunteered to move positions, and he eventually started at right guard in the 49ers’ third exhibition game.

When Davis left the 49ers in June 2015, he said he’d given it a “few years of thought.” He planned to step away for a “year or so” and allow his brain and body to heal from the previous five seasons as their starting right tackle.

With Davis not yet back on the roster, the 49ers traded up to draft a guard in Stanford’s Joshua Garnett with the 28th overall pick. Zane Beadles, their only free-agent acquisition on the current roster, is expected to start at left guard.

As recently as Friday, Kelly spoke on how he was counting on Davis in his starting lineup, where he’d be pitted Monday night against the Rams’ Aaron Donald, last season’s runner-up as NFL Defensive Player of the Year.

“I think Anthony is very athletic when it comes to offensive linemen,” Kelly said. “But, you know defensive linemen are usually a little bit more athletic than any offensive lineman. That’s kind of how those guys get parceled out. But Anthony’s a lot bigger and a lot more physical. So, there’s a give and take there.”

Davis earned rave reviews when he opened camp July 31 at 332 pounds, some 35 pounds lighter than his previous season in 2014, which was marred by several injuries, including a concussion.

“It’s hard work to get back to playing better than I was when I left,” Davis said Aug. 10. “It takes a lot of attention to detail, thinking about it all the time, cutting out distractions and pretty much start from the ground up. But it’s building pretty fast.”

Starting quarterback Blaine Gabbert on Thursday called the projected starting offensive line “phenomenal” and that the unit’s depth was the best he’s been around in six years as a pro. “It’s been fun to watch and there’s only going to be continued improvement throughout the year, especially with A.D. and Trent being new together on the right side,” Gabbert said. “It’s just going to keep getting better from here on out.”

The only other 49ers player who didn’t practice Saturday was nickel back and return specialist Chris Davis, who’s listed as doubtful for the opener after missing practice all week because of a hamstring strain. Cornerback Keith Reaser (ankle), linebacker Nick Bellore (knee) and defensive tackles Arik Armstead (shoulder), Quinton Dial (knee) and Glenn Dorsey (knee) are probable to play.

The Rams ruled out three backups: cornerback E.J. Gaines (thigh) and wide receivers Pharoh Cooper (shoulder) and Nelson Spruce (knee). Questionable are linebacker Bryce Hager (concussion) and offensive tackle Rob Havenstein (foot).