The Seattle Mariners’ first grand slam of spring training came from an unlikely source.

Notebook: M’s prospect ‘stole the show’ in Cactus League opener

In the first inning of Seattle’s second Cactus League game on Saturday, utilityman Miles Mastrobuoni turned on a first-pitch fastball from San Francisco Giants right-hander Hayden Birdsong and pulled it over the right-center-field fence at Peoria Stadium for a grand slam.

The moment gave legendary Mariners play-by-play voice Rick Rizzs – who is retiring at the end of this season after 41 years in the booth – an opportunity to break out the famous line: “Grandma, get out the rye bread and mustard! It is grand salami time!”

Mastrobuoni also doubled in Seattle’s 7-4 win over the San Diego Padres in Friday’s Cactus League opener.

Mastrobuoni appeared in 76 games for the Mariners last season, slashing .250/.324/.296 with one homer and four doubles. He offered late-inning versatility off the bench and played every position except catcher, shortstop and center field – even making a pitching appearance in a blowout loss.

The 30-year-old Mastrobuoni likely faces an uphill climb to make the Mariners’ opening day roster, with Seattle set to have possibly its deepest and most versatile lineup in decades. But early on, his spring is off to a good start.

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