Yastrzemski attended St. John's Preparatory School in Danvers, Massachusetts. Yastrzemski played for the school's baseball team, and was named team captain in his senior year. He committed to attend Vanderbilt University, on a college baseball scholarship. Seen as a potential early round selection in the 2009 Major League Baseball draft, Yastrzemski indicated that he would attend college unless chosen in the first round. The Boston Red Sox selected him in the 36th round of the 2009 MLB Draft. Yastrzemski did not sign with the Red Sox, and instead enrolled at Vanderbilt to play for the Vanderbilt Commodores baseball team. Yastrzemski became a starter for the Commodores in the middle of his freshman year. In 2010 and 2011, he played collegiate summer baseball with the Cotuit Kettleers of the Cape Cod Baseball League. After his junior year, the Seattle Mariners selected him in the 30th round of the 2012 MLB draft. The Mariners offered Yastrzemski a $300,000 signing bonus, well above the suggested bonus for a player chosen in that round. Yastrzemski chose not to sign, and returned to Vanderbilt for his senior year. As a senior, Yastrzemski was named All-Southeastern Conference. The Baltimore Orioles selected Yastrzemski in the 14th round of the 2013 MLB draft, and he signed.
Professional career
Baltimore Orioles
After signing with the Orioles, Yastrzemski began his professional career with the Aberdeen IronBirds of the Class A-Short SeasonNew York–Penn League, where he had a.273 batting average, three home runs, and 25 runs batted in. He appeared in the NY-P all-star game. Yastrzemski began the 2014 season with the Delmarva Shorebirds of the Class ASouth Atlantic League, where he batted.306 with 10 home runs and 44 RBIs. He appeared in the SAL all-star game. After the all-star game, he was promoted to the Frederick Keys of the Class A-AdvancedCarolina League, where he batted.312 in 93 at-bats. He was then promoted again, to the Bowie Baysox of the Class AAEastern League. Between Frederick and Bowie, Yastrzemski combined to bat.288 with 14 home runs, 18 stolen bases in 24 attempts, and 18 triples, which led all of Minor League Baseball. He was an MiLB Orioles organization All Star. Yastrzemski spent the 2015 season with Bowie, where he batted.246 with six home runs and 59 RBIs. He was a 2015 Eastern League All Star. He spent 2016 with both Bowie and the Norfolk Tides of the Class AAAInternational League, where he posted combined statistics of a.234 batting average, with 13 home runs, and 59 RBIs. Yastrzemski underwent surgery after the 2016 season and was not healthy for the beginning of the 2017 season. During the 2017 season, he was with the Tides for 81 games between May and September, except for several weeks in June and July when he played 20 games with the Baysox. He returned to Norfolk in 2018. He was an MiLB Orioles organization All Star. The Orioles invited Yastrzemski to spring training as a non-roster player in 2019. On March 22, 2019, the Orioles traded Yastrzemski to the San Francisco Giants in exchange for minor league pitcher Tyler Herb. He was assigned to the Sacramento River Cats of the Class AAA Pacific Coast League to start the 2019 season, for whom he batted.316/.414/.676 with 38 runs, 12 home runs and 25 RBIs in 136 at bats.
San Francisco Giants
The Giants promoted Yastrzemski to the Major Leagues on May 25, 2019, and he made his debut the same day, going 0-for-3 with a run scored in a 10–4 loss to the Arizona Diamondbacks. He collected his first career hit, a single, the following day but was thrown out returning to first base and went 3-for-4 with a run scored in the Giants 6–2 loss. Yastrzemski hit his first career home run against his former organization, the Baltimore Orioles, off Andrew Cashner on May 31. On August 16, he hit three home runs against the Arizona Diamondbacks at Chase Field, including the game-winning home run in the top of the 11th inning. On September 17, he hit his 20th home run, a solo shot to the center field bleachers, in his first game at Fenway Park, where his grandfather played his entire 23-year MLB career. The Giants won 7–6. For the 2019 season, Yastrzemski played in 107 games while batting.272/.334/.518 with 21 home runs, 55 RBIs and 64 runs scored in 371 at bats. His 21 home runs tied Kevin Pillar for the most on the team.
Personal life
Yastrzemski grew up in Andover, Massachusetts. His father, Carl Jr., played college baseball for the Florida State Seminoles baseball team, and played professionally in the minor leagues from 1984 to 1988. His father and mother, Anne-Marie, divorced when he was six years old. Carl Jr. died at the age of 43 from a blood clot after having hip surgery. His grandfather, Carl Yastrzemski, is a member of the National Baseball Hall of Fame and began teaching young Mike hitting during his grandson’s freshman year in high school. Yastrzemski married his wife, Paige Yastrzemski, in December 2018.
