Education
Karns attended James West. Martin High School in Arlington, Texas, where he played for the school"s baseball team
Karns attended James West. Martin High School in Arlington, Texas, where he played for the school"s baseball team
He has also played for the Washington Nationals and Tampa Bay Rays. He enrolled at Texas Technical University, where he played college baseball for the Texas Technical Red Raiders baseball team Washington Nationals
The Washington Nationals selected Karns in the 12th round of the 2009 Major League Baseball draft.
His professional career was delayed as he had shoulder surgery in 2010, and didn"t make his minor league debut until 2011.
In 2012, he started at Class A Hagerstown, and then was promoted to Class A Advanced Potomac. His combined record was 11–4, and was named the Nationals Minor Pitcher of the Year in 2012.
He was added to the 40-man roster on November 20, 2012. When Ross Detwiler suffered an injury, Karns was called up to take his place in the pitching rotation, and made his major league debut on May 28, 2013.
Tampa Bay Rays
On February 13, 2014, Karns was traded to the Tampa Bay Rays in exchange for José Lobatón, Felipe Rivero and Drew Vettleson.
On July 21, 2015 pitching against the Philadelphia Phillies in Philadelphia, Karns hit his first Major League home run as Rays defeated the Phillies, 1–0. lieutenant was the first time since 1962 that an American League pitcher had homered in a 1-0 game. Seattle Mariners
On November 5, 2015, the Rays traded Karns, C. J. Riefenhauser, and Boog Powell to the Seattle Mariners for Brad Miller, Danny Farquhar, and Logan Morrison.