Zunino enters his sixth season after setting several career highs at the plate. No catcher currently in Mariners spring training has close to the same big league experience as the 26-year-old Zunino.
He hit .251 with 25 home runs and 64 RBIs last season. Zunino caught 994 innings, the second-most in the American League.
An early-season demotion to Triple-A, which became an annual event as he struggled with his hitting, helped him figure out what needed to change.
"When I got sent down, I made some major swing adjustments, more so than years past," Zunino said. "It was something that came rather quickly. It felt natural. Obviously, getting the results to follow that is always nice."
Zunino narrowed his swing, incorporated a leg kick and changed the direction of his swing to focus more on hitting to the middle of the field.
"It was just sort of building it from the ground up again," he said.
He was recalled from Tacoma on May 22 and had a June to remember. Zunino hit .304 with 10 home runs and a major-league leading 31 RBIs that month. He hit .281 after the All-Star break.
Manager Scott Servais said Zunino is taking more of a leadership role after a successful season.
"You see it right away. I was anticipating we'd see a little different guy in spring training, and there's no question," Servais said. "Just from a confidence standpoint, his ability get up and lead meetings and talk to the pitchers. It's about signs, it's about sequence, things you want to do different than last year.
"The confidence level is through the roof, and it should be. He's a really good player and now starting to show out on the field."
The Mariners begin spring training play Friday against complex neighbor San Diego. Servais said most Opening Day regulars won't play. ... CF Dee Gordon will play against the Padres, getting acclimated to a new position. ... Servais said he has the most talent and depth in the bullpen as he enters his third season with the team. ... RHP Tony Zych is coming back from forearm soreness and won't pitch in games right away.