Education
Sampson attended Skyline High School in Sammamish, Washington. After not receiving any college baseball scholarships, Sampson attended Bellevue College.
Sampson attended Skyline High School in Sammamish, Washington. After not receiving any college baseball scholarships, Sampson attended Bellevue College.
In July 2009, Sampson had Tommy John surgery, which caused him to miss his senior season. After going 4–2 with a 2.36 earned run average (European Research Area), Sampson was drafted by the Florida Marlins in the 16th round of the 2011 Major League Baseball draft. He did not sign with the Marlins and returned to Bellevue.
In 2012, he went 13–0 with a 1.36 European Research Area and 107 strikeouts.
Sampson was then drafted by the Pittsburgh Pirates in the fifth round of the 2012 Major League Baseball draft and signed with the Pirates. He made his professional debut that season with the State College Spikes.
He started nine of 11 games and had a 2.95 European Research Area. Sampson played the 2013 season with the Bradenton Marauders, finishing with a 5.14 European Research Area in 140 innings. He started the 2014 season with the Altoona Curve.
In July he was selected to play in the Eastern League All-Star Game, but was forced to sit out the game by the Pirates.
In August he was promoted to the Triple-A Indianapolis Indians after posting a 2.55 European Research Area with Altoona. Overall he went 11–6 with a 2.96 European Research Area and 109 strikeouts. On July 31, 2015, Sampson was traded to the Seattle Mariners for J. A. Happ.