Last year at this time Marco Gonzales was still recovering from a torn ulnar collateral ligament that required Tommy John surgery.

And now? He’s poised to make his first start of the season on Tuesday at San Francisco after experiencing his first major-league Opening Day in Seattle, just a few hours from where he played college baseball for Gonzaga.

“It’s night and day different for me (from 2017),” Gonzales said. “It’s a beautiful thing to have a healthy arm and it’s a beautiful thing to have an opportunity like this. So I’m not taking anything for granted.”

And a healthy, effective Gonzales could be the key that holds this Mariners’ starting rotation together.

He’s now two years removed from Tommy John surgery on his left throwing elbow, which is apparently the make-or-break point for pitchers coming off the surgery. His velocity is better than before, he’s found an arm slot he thinks works for him and he’s even expanded his repertoire to include a cutter.

All that and a solid spring led manager Scott Servais to think that Gonzales could surprise people more than any other Mariner this season.

“That’s what we anticipated when we acquired him,” Servais said. “We knew that last year was his first full year and now it’s his second full year off it, and now he’s got all of his weapons and he’s attacking hitters a little differently than we saw last year.”

Gonzales will get his first chance to show his improvement when he starts in the Mariners’ 1:35 p.m. game against the Giants.

Servais faced questions regarding their rotation seemingly every day this spring, and general manager Jerry Dipoto was oft-criticized for not digging through the free-agent pool for an experienced starter. But that’s because the Mariners’ braintrust feels better about their crop of starters than most.

“I do,” Servais said in the final week of spring training. “And I feel like a lot of it is triggered off of Marco Gonzales, quite frankly.

“I think Marco has had an outstanding spring and it’s what we expected he could do. He looks very strong. All of his pitches are there.”

Gonzales landed with the Mariners’ organization last summer in a trade that sent outfielder Tyler O’Neill to the St. Louis Cardinals.

At the time the Mariners desperately needed starting pitching and the 26-year-old former first-round draft pick from the Zags was quite appealing, even if he was coming off of surgery and had pectoral and shoulder injuries that had delayed his development.

Besides, what other Mariners’ starter has pitched in the National League Championship Series?

Answer: none.

Gonzales was 22 when he was thrown into service in the NLCS for the Cardinals against the Giants — the same team he’ll open against in his 2018 debut on Thursday. He appeared in eight postseason games in that run, and three against the Giants.

Gonzales was hanging his head in the Cardinals’ dugout after he was charged with three runs in relief in a 6-4 loss, his first runs allowed of the postseason. Though some defensive mistakes that inning didn’t help his cause.

“That happened at such an early stage of my career,” Gonzales said. “I really didn’t know what that was about and it was hard for me to grasp. But I think when we get back there, I think it will be like those feelings will all come back. It was such a blur and I really didn’t know what to do with it, so hopefully I get another chance at that.”

Gonzales also earned two wins in relief in the NLDS against Dodgers.

Given his success as a reliever — and the issue of getting deep into games, something that plagued him last year — why not out use Gonzales out of the bullpen?

The Mariners think the addition of a cut fastball this year will help Gonzales in what was his bane last season — getting through a lineup for the third time. He didn’t use the cutter last season because he was still getting comfortable with his arm off the surgery.

And it’s a pitch he relied on often before his injury. Gonzales said it was effective much of spring.

“It’s been a big pitch for me and using it backdoor outside to righties,” Gonzales said. “It’s something I’m excited about, for sure.”

Servais just had to remind him not to overuse it.

“He had one start where he threw like 16 of 17 and that’s not what we’re looking for,” Servais said. “I think it’s a pitch he uses seven or eight times in a ball game to right-handed hitters, and I think he’s even thrown some good ones to lefties that turns more into a slider off his fastball.

“I think it can be a really effective pitch, but it’s definitely not one he should overuse. It’s still fastball, changeup and the curveball that has been much better this spring. He’s got a nice package of stuff to offer.”

That’s what the Mariners were anticipating and why they say they completed their 2018 pitching search in the middle of 2017, when they acquired Gonzales, Erasmo Ramirez and Mike Leake.

So what rotation questions?

“There were no questions in our minds,” Gonzales said. “We’re going to go out and win ball games.

“The expectations I have for myself are high. Being able to execute pitches, I think I have a high standard for that and that’s something I would like to get better at. But as far as my arm health, I couldn’t feel better about that. That’s been great. It’s just finding a routine that works for me and just learning from every outing.”