He has previously played in Major League Baseball (MLB) with the Kansas City Royals and Toronto Blue Jays.

The Kansas City Royals selected him in the first round of the 2014 Major League Baseball draft.

In 2016, Griffin split time between Lexington and the Wilmington Blue Rocks, where he posted a combined 6–4 record and a 5.43 ERA between the two teams.

[8] Griffin made his major league debut on July 27, 2020, and pitched 1+2⁄3 scoreless innings to earn the win against the Detroit Tigers.

[12] On July 16, 2022, Griffin traded to the Toronto Blue Jays in exchange for Jonatan Bernal.