Boldt is naturally left-handed, but taught himself to throw with his right arm after having surgery to repair a broken radial head in his left elbow at the age of 10.

In the fall of 2012, Boldt was named the most valuable player of the Perfect Game High School All-American Classic,[3] and competed on the United States national team in the 2012 18U Baseball World Championship, winning the gold medal.

[10] In 2016, Boldt was named to the Golden Spikes Award watchlist, and ranked as one of the best prospects available in the 2016 Major League Baseball draft.

[12] Boldt signed with the Rays[13] and spent his first professional season with the Hudson Valley Renegades of the Low-A New York-Penn League, where he posted a .218 batting average with one home run and 15 RBIs in 43 games.

[14] Boldt spent 2017 with the Charlotte Stone Crabs of the High-A Florida State League, batting .295 with five home runs and 62 RBIs in 120 games.