Stephen Pryor was drafted by the Texas Rangers in the 42nd Round of the 2008 MLB Draft, but then elected to play for Tennessee Tech for two seasons. He then was drafted by the Seattle Mariners in the 5th Round of the 2010 MLB Draft. Pryor then went on to play for the Everett AquaSox (A) and the Clinton Lumberkings (A) in 2010, the High Desert Mavericks (A+) and Jackson Generals (AA) in 2011 and 2012 as well as the Tacoma Rainiers in 2012. Pryor was then called up to the Seattle Mariners and appeared in MLB games for the team in 2012, 2013, and 2014 while alos playing for the Generals, Rainiers, and Rochester Red Wings (AAA) in this time frame. Pryor then finished out his professional career playing for the GCL Twins (ROK) and Red Wings in 2015. 

In the minors, Pryor posted a 3.69 ERA with 243 strikeouts in 205.0 innings pitched. He also had a 2.81 ERA with 35 strikeouts in 32.0 innings pitched for the Mariners.