Career
Sampson was drafted by the San Diego Padres in the fourth round of the 2009 Major League Baseball Draft. In 2010 he went 12-3 with a 2.90 earned run average and 143 strikeouts in 118 innings pitched. He started the 2013 with the Triple-A Tucson Padres but was demoted to Double-A San Antonio Missions after posting an 8.03 European Research Area. He was promoted back to Triple-A on August 7, 2013 after going 10-4 with a 2.26 European Research Area in Double-A. He was added to the Padres 40-man roster on November 20, 2013.
Sampson was designated for assignment on December 29, 2014.
On January 8, 2015, he was claimed off waivers by the Cincinnati Reds. The Reds promoted Sampson to the major leagues on July 30.