Before Sunday night, Andrew Tiller’s NFL career had included two tears and one snap.

First, those tears.

As a rookie with the Saints in 2012, the 49ers right guard tore his biceps in the preseason opener and spent the season on injured reserve. In 2013, he sustained a less severe biceps injury in training camp, missed three preseason games and was among New Orleans’ final roster cuts. In 2014, he tore a calf muscle in training camp with the Packers and was cut before the regular-season opener.

Thanks partly to his painful preseasons, Tiller, a sixth-round pick, had played one regular-season snap, spent time on three teams’ practice squads and had been waived five times in his first 41 months in the league.

“Those always haunted me,” Tiller said. “The biggest thing for me has been just dealing with injuries.”

Tiller, 26, is now healthy and is happily dealing with this: speculation he could make his first NFL start Sunday when the 49ers host the Ravens.

Tiller rotated series with struggling starter Jordan Devey in last weekend’s 30-27 loss to the Giants, making his first appearance on their third series. Tiller and Devey each played 34 snaps and the new guy made a case for more playing time: Tiller, who is best known for his run-blocking ability, didn’t allow a quarterback pressure on 26 pass-blocking snaps, according to Pro Football Focus.

Offensive coordinator Geep Chryst acknowledged the 49ers would prefer to not play musical chairs at right guard.

“Eventually you’d like to have stability,” Chryst said. “We’re providing both of them an opportunity and I thought Andrew took advantage of it.”

So will he start Sunday? Tiller’s answer included an I’m-not-telling-you laugh: “I have no idea,” he claimed. “I just do what I’m told.”

Tiller has reason to smile given recent events. Two days before kickoff last Sunday, head coach Jim Tomsula told him he had been promoted from the practice squad and would be active against the Giants. The news came just before the 49ers boarded a flight to play in East Rutherford, N.J., an area Tiller knows well: He attended Syracuse and grew up in Queens and Central Islip, N.Y., which are both less than 60 miles from MetLife Stadium.

“My first time seeing real NFL action and it’s back home on Sunday night football?” Tiller said. “That’s more than anybody can really ask for. It doesn’t get much better than that.”

Tiller earned the promotion because he’s gotten better since he was among the 49ers’ final roster cuts in September. After he was signed to the practice squad a day after his release, Tiller, 6-foot-3, continued dropping weight and addressed some technique issues raised by the coaching staff.

Tiller, who weighs 318 pounds, has dropped about 10 pounds since training camp. The weight loss has allowed him to move better in a zone-blocking scheme that requires plenty of pulling from guards.

One of those guards, Alex Boone, was impressed by Tiller’s 2015 debut.

“He’s aggressive,” Boone said. “He’s a perfect guard. He did a great job Sunday and I think he’ll continue to do well for us.”

Tiller acknowledges he was disappointed not to make the season-opening roster. The 49ers kept three guards: Devey, who was acquired in a trade with the Patriots in mid-August, Ian Silberman and Brandon Thomas. Silberman is a rookie sixth-round pick and Thomas was selected in the third round in 2014.

“If you don’t make it and you’re not disappointed, you don’t need to be in this profession,” Tiller said. “You’re not going to be here too much longer because you’re not hungry enough. Of course, I was disappointed, but you can’t let that get you down. You just have to keep grinding and get better in the areas they thought you were lacking at.”

Despite his under-the-radar career, Tiller insists he’s had an unwavering belief he’d shine if he could stay healthy. Now, in his fourth NFL season, he’s never felt better.

“I just know than I’m better than just being on the practice squad,” he said. “I know that’s just not me. I know that I belong.”

Eric Branch is a San Francisco Chronicle staff writer. E-mail: ebranch@sfchronicle.com. Twitter: @Eric_Branch