Miles Mastrobuoni is making a major statement early in Mariners' Spring Training

Considered a long shot to make the Major League roster, Miles Mastrobuoni hit a grand slam against the San Francisco Giants on Saturday, as he tries to catch the eyes of the coaching staff

Jun 28, 2025; Arlington, Texas, USA; Seattle Mariners third baseman Miles Mastrobuoni (21) catches a pop fly hit by Texas Rangers left fielder Alejandro Osuna (not pictured) during the fourth inning at Globe Life Field. Mandatory Credit: Jerome Miron-Imagn Images | Jerome Miron-Imagn Images

Considered a long shot to make the Major League roster, Miles Mastrobuoni struck again, crushing a grand slam in the first inning against the San Francisco Giants on Saturday, as he tries to catch the eyes of the Seattle Mariners' coaching staff. The 30-year-old utility player also doubled in Friday's opener, going 1 for 2 in that match-up.

While there are several names ahead of him in terms of the M's food chain, including top prospect Colt Emerson and young players Leo Rivas and Cole Young, Mastrobuoni is doing all the things a dark horse must do to place in the race.

"He's probably on the outside looking in to an Opening Day roster spot, and out of Minor League options, but the Mariners like a lot about what he does as a multi-positional lefty bat," MLB.com writer Daniel Kramer posted early in the contest.

Miles Mastrobuoni crushes a grand slam, as the Mariners open up a five-spot in the 1st inning.

He's probably on the outside looking in to an Opening Day roster spot, and out of Minor League options, but the Mariners like a lot about what he does as a multi-positional lefty bat. pic.twitter.com/DNSfX3etlt

— Daniel Kramer (@DKramer_) February 21, 2026

In 195 career MLB games with the Tampa Bay Rays, Chicago Cubs, and Mariners, Mastrobuoni has a .231 career batting average, with two home runs, 21 RBI, and .572 OPS. He can play third base, second base, and both corner outfield spots.

Miles Mastrobuoni has even made multiple appearances in mop-up duty on the mound, but owns a 27.00 ERA as a big-league hurler for his troubles. Mastrobuoni was acquired by the Mariners from the Cubs for cash in January 2025.

Miles Mastrobuoni has the right mindset

Jun 15, 2025; Seattle, Washington, USA; Seattle Mariners third baseman Miles Mastrobuoni (21) hits an RBI-single against the Cleveland Guardians during the second inning at T-Mobile Park. Mandatory Credit: Joe Nicholson-Imagn Images | Joe Nicholson-Imagn Images

Mastrobuoni has no misconceptions as to where he stands as a player; he's considered a contributor, not a star. But, he's fine with that role, embracing it by bringing many positive attributes and the right attitude to the Spring competition. He commented on what he feels is his best strategy for success

"A lot of hard work is kind of an obvious one," Mastrobuoni commented about his game. "But just kind of keeping my head down, staying focused, taking it one year at a time. I preach a lot about just being where your feet are and taking it one level at a time and conquering it."

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