Bay regained health and reworked his swing in this offseason, and it's already paying dividends.
Bay hit a two-run homer in his first spring at-bat and the Mariners went on to beat the San Diego Padres 8-6 Saturday.
"I tried a million things to get my swing back and to save face," said Bay, who signed a one-year $1 million contract this offseason. "Nothing was working, and I got so far away from where I was before that I forgot how to do it. The goal heading into this spring is to get back to doing what I've always done."
"When you get instant feedback like that first-inning home run, that speaks volumes that you're on the right track," he said.
Bay redirected a 95 mph fastball from Padres starter Tyson Ross over the left-field wall. He also walked twice.
A big hitter earlier in his career, Bay floundered after signing a four-year, $66 million deal with the New York Mets. The outfielder was physically hobbled and mentally drained during his time in New York, but Seattle gave him a chance to start fresh.
Bay must play his way onto the 25-man roster with a solid spring, an odd predicament the three-time All-Star doesn't seem to mind.
"I understand that there are people for a limited number of roster spots, but I'm not concerned about a competition," Bay said. "I'm concerned about me. I want to make a good impression here, and I know I still have to make the team. I kind of like that because, if I make this team, it means I deserve it."
Seattle first baseman Justin Smoak, a switch-hitting cleanup hitter who underwhelmed with a .217 average in 2012, homered from the left side of the plate.
Reserve shortstop Jeudy Valdez homered, doubled and drove in three runs for the Padres. San Diego scored five times in the ninth.
Highly touted Seattle pitcher Taijuan Walker gave up a hit in his one-inning spring debut, which featured a fastball that reached 97 mph.
Mariners prospect Danny Hultzen struck out two in an inning.
Ross, a contender for a spot in the Padres' rotation, allowed three hits and a walk in two innings.
"They were throwing consistent strikes and getting in pitcher-friendly counts," Padres manager Bud Black said. "We were doing the opposite, which led to some of their early offense. We played better late in the game, but we didn't get much going early."
Padres 3B Chase Headley will make his spring training debut on Sunday, Black said. Also set to play for the first time are OF-1B Mark Kotsay and CF Cameron Maybin, who has been limited in early spring due to wrist soreness. ... Padres P Edinson Volquez is scheduled to start Monday against Milwaukee at Maryvale, Ariz., the first of two outings prior to joining the Dominican Republic for the World Baseball Classic. ... Seattle will start Erasmo Ramirez on Sunday against the Padres, and Jeremy Bonderman on Monday against the Los Angeles Angels.