PEORIA, Ariz. — The difference is striking. A year and a day ago, Guillermo Heredia arrived at the Mariners’ spring-training complex unaware and unsure of what would follow.

A Cuban defector who had sat out for all of 2015, he was signed to a free-agent contract days into spring training. His first taste of organized baseball in the United States came at the highest level — big-league spring training with the Mariners. Nothing about this existence was familiar other than fellow Cuban Leonys Martin, whose locker was next to him.

That uncertainty of belonging often left him sitting quietly in front of his locker, staring at his phone or at the array of new faces he did not know and many he couldn’t communicate with, not that he had a reason to.

Fast forward to Sunday morning in the same clubhouse and Heredia is headed for that same locker. He stops and talks with a handful of Latin pitchers near the pool table, converses with Tyler O’Neill in English and says “good morning” to multiple Mariners staffers. After taking a seat in the chair in front of his locker, he jaws with Nelson Cruz and Robinson Cano as well utilityman Shawn O’Malley.

“It’s definitely more comfortable,” he said through interpreter Fernando Alcala. “It feels more like a family. You know everybody. You can talk to everybody. Everybody has been helping me, not just on the field but with English as a language.”

The scared kid yearning to fit in has been replaced with a confident man with a sense of belonging.

“Totally different guy,” manager Scott Servais said. “You talk about just signing, showing up in this camp … to where he has come in a year.”

Going into last spring training, Heredia was just hoping to be signed by a team and attend a camp. The entire process from defecting to signing took almost a year. He spent much of that time working out on his own and preparing for showcases for MLB scouts. He had played just one organized game in two years when he arrived to the Mariners.

“The biggest thing is preparation,” Heredia said. “Last year, the thing on my mind was just getting to spring training. I didn’t have the preparation to have success here. But I do now.”

Despite a two-year layoff, the Mariners got more than they expected out of Heredia, who was projected to be a solid defensive player and base runner and a question mark at the plate.

They deliberately worked him in slowly in spring training and then starting him at Class AA Jackson, where he hit .293 with a .405 on-base percentage with seven doubles, two triples, two homers and 34 RBI in 58 games. Heredia was promoted to Class AAA Tacoma on June 23 and played in 35 games, hitting .312 with a .378 on-base percentage.

He made his big-league debut on July 29. He had a two-week stint in the big leagues, was sent down to Tacoma and recalled again in late August and remained with the Mariners. He hit .250 with a .349 on-base percentage three doubles, a homer and 12 RBI in 45 games. The Mariners used him heavily as a late-inning defensive replacement in left field.

“What we saw last year, there were some flashes,” Servais said. “He just brought a different dynamic to our outfield when he was out there. The number of plays made, running balls down, the arm and also the ability to play center field at a high level. Really it was desperately needed last year.”

After playing in one organized game in two years, he had made the big leagues.

“That was one of the greatest opportunities that I’ve had in my life,” he said. “To get to do that, you do appreciate it, and I’m going to keep working to keep that going.”

It also provided verification for the difficult decision to defect and put his career on hold for a year while leaving his friends and family behind.

“It’s obviously very hard,” he said. “When you are in Cuba, you don’t think about that as part of your decision. When you are somewhere else, it becomes really hard. But I draw strength from that and move on and use it as motivation and try to help them from here.”

The presence of Martin and the midseason addition of Ariel Miranda helped Heredia adjust.

“They’re part of the process,” he said. “Having them here is helpful, while we may not have our own families here, the three of us are family and we help each other move forward each day.”

Heredia comes into camp fighting for a spot on the 25-man roster. Logically he fits as the fourth outfielder and right-handed hitting compliment to Jarrod Dyson in left field. The Mariners trust his ability on defense and on the bases. But they asked him to get better offensively.

“I think the thing that at times would get him in trouble — he’s not a power guy by any means — it’s the soft fly balls to right field,” Servais said. “I would rather have him roll a ball over to the left side and have a chance of beating that out then flipping a ball in the air to right field. It’s not going to go out of the park. He’s not Nelson Cruz in the box.”

Heredia went to the Arizona Fall League to retool his swing with Mariners minor-league coach Brant Brown. The Mariners wanted a shorter, flatter and more compact swing.

“It’s been a hard adjustment,” Heredia said. “I’ve had the same swing for a long time, so to make that adjustment now and to have success now it’s very welcoming.”

He had three hits in his first three at-bats this spring.

“I was really excited what I saw offensively,” Servais said. “Not just because he got three hits yesterday, we’ve seen it in batting practice out here and some of the adjustments he’s made. He’s flattened out his swing path a little bit. His swing is shorter right now than it was last year. That is something he worked on at the end of the year. I give him credit, he looks great.”

If he continues to look great, it will earn him a spot on the roster. Servais trusts him in the outfield at all three positions and on the bases.

“It’s the same characteristics that make me who I am — the defense, the leadoff ability, the ability to steal a base,” Heredia said. “Those are the characteristics I need to work on and show them here on the field.”

Heredia knows he’s prepared to handle a spot on the opening-day roster.

“I’m a better player today than I was yesterday and a year ago,” he said. “I think you pick up little things along the way. The sacrifice is part of the process. Every little bit has helped to get me to where I am now.”