The Seattle Mariners are all set for Spring Training action

On-field action begins for the Mariners right away, starting with the Cactus League opener Friday afternoon against the Padres at Peoria Stadium

Jul 24, 2025; Anaheim, California, USA; Seattle Mariners manager Dan Wilson (6) looks on during batting practice prior to the game against the Los Angeles Angels at Angel Stadium. Mandatory Credit: Jayne Kamin-Oncea-Imagn Images | Jayne Kamin-Oncea-Imagn Images

On-field action for the 2026 Seattle Mariners officially begins Friday afternoon, starting with the Cactus League opener against the Padres at Peoria Stadium. The two teams share the same complex and will also close out the Spring schedule at the conclusion of camp. Game time this afternoon is set for 12:10 PT.

Right-hander Dane Dunning, a non-roster invitee, will start the Cactus League opener for the Mariners, who enter exhibition play with an MLB-high 16 players taking part in the World Baseball Classic. However, the team has a contingency plan in place to weather the WBS storm and still be ready to roll on Opening Day.

“We’ve kind of mapped out what these guys need in terms of that,” M’s manager Dan Wilson told multiple media members on Thursday.
“It’s baseball, so you always have to be able to adjust. But I think we’re in a pretty good spot with understanding what they need and also trying to build them up as much as possible.”

The Mariners' pitching staff will be handled with care

Jul 30, 2025; West Sacramento, California, USA; Seattle Mariners starting pitcher Bryan Woo (22) throws a pitch against the Athletics during the first inning at Sutter Health Park. Mandatory Credit: Dennis Lee-Imagn Images | Dennis Lee-Imagn Images

The Mariners' rotation of Bryan Woo, Logan Gilbert, George Kirby, Luis Castillo, and Bryce Miller will be brought along with a slow build in their workload. This could be especially beneficial to players like Miller and Woo, who battled injuries last season.

In 2025, Woo emerged as the ace, posting a 15–7 record with a 2.98 ERA and 198 strikeouts, finishing fifth in AL Cy Young voting and being selected to his first All-Star team. Due to the pectoral injury, however, he would throw just 186.1 innings, a total he wants to improve on in 2026. He's stated that his goal for the upcoming season was to surpass the 200-inning mark.

Woo threw his first live BP session on Wednesday, and his fastball clocked in at around 95 mph. Dan Wilson noted that his righty starter is focused and ready for another positive year in 2026.

“He was all business getting his work in,” Wilson said.

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