PEORIA, Ariz. -- A 633-day, injury-plagued, mentally taxing hiatus ended on Sunday when Mitch Haniger stepped into the batter¡¯s box during the first inning of the Mariners¡¯ 5-4 win over the Padres in their Cactus League opener.

By that point for the Mariners¡¯ methodical right fielder, it was just another at-bat. The rigorous and specialized rehab he had conducted in the offseason was complete, and the batting practice reps he¡¯d taken since reporting to Spring Training early gave him conviction that he was prepared to take the field. There was no existential feeling of fulfillment while he awaited in the on-deck circle.

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It was all business for Haniger, who roped an infield single and gave the Mariners -- and himself -- further validation of his health status entering the 2021 season.

¡°I was excited,¡± said Haniger, out since June 6, 2019, because of multiple injuries and surgeries. ¡°Definitely some nerves -- good to feel those again. I feel those every Spring Training and pretty frequently during the season, too. But I think the last couple days, having live BPs, that really helped me prepare. I came down here a little early to stand in on some bullpens, and yeah, I've been feeling good, ready to go. The biggest thing for me is just missing the competition.

¡°When you're on the on the [injured list] for so long, it's tough to find that fix with competition, and that's what I missed the most.¡±

For all the hype that the Mariners¡¯ up-and-coming talent has received this offseason, Haniger could represent their biggest addition for 2021. General manager Jerry Dipoto put it bluntly in January, saying that a healthy Haniger ¡°is our best player.¡± If Haniger finds any semblance of his ¡¯18 form -- when he was an All-Star, had a slash line of .285/.366/.493 with 26 homers and a 6.2 bWAR -- there is support for Dipoto¡¯s conviction.

But that won¡¯t prevent the Mariners from exercising caution with their high-valued commodity. Haniger struck out in his second at-bat, in the third inning, and then he was pulled in the top of the fourth for Jarred Kelenic, who went on to score the game-winning run on a walk-off single by Julio Rodr¨ªguez.

Seattle says shorter days for Haniger -- and many of its everyday players -- will be the norm as the club prepares to go from a shortened season back to 162 games. Haniger will remain in contact with manager Scott Servais, head athletic trainer Kyle Torgerson and the rest of the training staff about where he best fits and on which days. Haniger likely will see a chunk of action at designated hitter, too.

¡°I think it's just kind of play-it-by-ear kind of thing, see how I¡¯m feeling¡± Haniger said. ¡°Right now, I'd like to play every other day.¡±

After a positive rehab process with the staff at Apiros, which specializes in optimizing body movements, Haniger will continue to conduct some of those exercises in camp on his own. He connected with Apiros before undergoing back surgery in January 2020, which followed his adductor tear surgery in September 2019 while attempting a late-season comeback. Both resulted from overcompensating during rehab from a ruptured testicle he sustained from a foul ball.

¡°When you're in the training room a lot, you don't get to spend a lot of time with your teammates,¡± Haniger said. ¡°It's good to be back on the field. A lot of characters in our clubhouse and a lot of fun friends make me laugh. So it's definitely been fun.¡±