Jackson Generals
In June 2010, Paxton was drafted by the Seattle Mariners in the fourth round of the 2010 Major League Baseball Draft. He signed with the Mariners on March 4, 2011. In the 2011 season, Paxton played for Single A Clinton LumberKings and the Double A Jackson Generals of the Southern League. He finished with a 6–3 win–loss record, 2.37 ERA, 131 strikeouts, and 43 walks in 95 innings pitched, while allowing an opposing batting average of .215. Paxton, along with Alex Liddi, represented the Mariners at the 2011 All-Star Futures Game. Paxton was invited to attend the Mariners' main spring training camp in 2012, but did not make the opening day roster. He was sent to the Jackson Generals.