He played in Major League Baseball (MLB) for the Seattle Mariners, San Diego Padres and Kansas City Royals.

After being overshadowed by other prospects, Maurer had a strong spring training showing with the Mariners in 2013, and made the team's Opening Day roster in the starting rotation.

Maurer signed a minor league free agent deal with the Pirates during prior to the 2019 season.

Maurer played for the school's baseball team, which competes in the Trinity League, within the Southern Section of the California Interscholastic Federation.

[1] Though he was overshadowed by teammates Gerrit Cole and Aaron Gates,[3][4] he earned notice from Major League Baseball teams.

Though overshadowed by teammates Danny Hultzen and Taijuan Walker,[4] Maurer was named the league's Most Outstanding Pitcher after going 9–2 with a 3.20 earned run average with 117 strikeouts in 137+2⁄3 innings pitched.

[11] In spring training in 2013, Maurer competed with Erasmo Ramírez, Jeremy Bonderman, and Blake Beavan for one of the final two spots in the Mariners' five-man starting rotation, behind Félix Hernández, Hisashi Iwakuma, and Joe Saunders.

[12][13] Allowing only two runs in 20 innings with 22 strikeouts and six walks in the Cactus League, Maurer made the Mariners' 25-man roster as a starting pitcher, skipping the Triple–A level.

[16] On December 30, 2014, the Mariners traded Maurer to the San Diego Padres in exchange for Seth Smith.

On July 24, 2017, the Padres traded Maurer, Ryan Buchter, and Trevor Cahill to the Kansas City Royals for Matt Strahm, Travis Wood, and Esteury Ruiz.

[22] In 8 games split between the Low–A West Virginia Black Bears and Triple–A Indianapolis Indians, he compiled a 3–0 record and 2.89 ERA with 13 strikeouts across 9+1⁄3 innings pitched.