McCarthy was born in Walnut Creek, California, and raised in Brentwood.
[4] The Boston Red Sox selected McCarthy in the 14th round of the 2011 MLB draft, and he reached Triple-A in 2014.
In 2018, he became the bullpen coach for the Rochester Red Wings, the Triple-A affiliate of the Minnesota Twins.
[1] In 2022, he was the pitching coach for the El Paso Chihuahuas, the Triple-A affiliate of the San Diego Padres.
[7] As of the 2024 season, McCarthy was named the pitching coach of the Gwinnett Stripers, the Braves AAA Affiliate.