[1] He struggled to be noticed by college baseball programs in the National Collegiate Athletic Association's Division I, as his fastball averaged 82–83 miles per hour (132–134 km/h).

Hoffman pitched in Connie Mack Baseball during the offseason to attract attention from college programs, where his fastball improved to 92 miles per hour (148 km/h).

[2] During his freshman year with the East Carolina Pirates baseball team in 2012, Hoffman started 10 of the 19 games in which he appeared, posting a 3–2 record, one save, a 3.67 earned run average (ERA), and struck out 55 batters in 72+2⁄3 innings pitched.

During the 2013 season Hoffman posted a 6–7 record, a 3.20 ERA, led the Pirates with 109+2⁄3 innings pitched and 84 strikeouts, was named to the All-Conference USA second team, and was added to the Golden Spikes Award watch list.

[3][4] In his junior year at ECU, Hoffman went 3–3 with a 2.94 ERA before suffering a torn ulnar collateral ligament in his right elbow injury that required Tommy John surgery.

He began throwing off a mound in February 2015,[15] and made his professional debut with the Dunedin Blue Jays of the High-A Florida State League on May 20.

[19] On July 28, 2015, the Blue Jays traded Hoffman, José Reyes, Miguel Castro, and Jesús Tinoco, to the Colorado Rockies in exchange for Troy Tulowitzki and LaTroy Hawkins.

In 2018, Hoffman spent the majority of the season at the Triple-A level, only making six appearances for the Rockies, in which he struggled to a 9.35 ERA with five strikeouts over 8+2⁄3 innings.

On November 25, 2020, the Colorado Rockies traded Hoffman and Case Williams to the Cincinnati Reds in exchange for Jameson Hannah and Robert Stephenson.

[30] He made nine appearances for the Triple-A Lehigh Valley IronPigs, with an 0-2 record while registering a 7.00 ERA with 7 walks and 16 strikeouts in 9 innings pitched.

On October 9, in Game 4 of the NLDS against the New York Mets, Hoffman exited with the bases loaded in the bottom of the sixth inning with a 1-0 lead for closer Carlos Estévez.

[38] It was later reported that Hoffman had also agreed to a five-year contract with the Atlanta Braves, but the team had also walked away from the deal after flagging an issue in his physical.