Education
Duffey attended Bellaire High School in Bellaire, Texas.
Duffey attended Bellaire High School in Bellaire, Texas.
He then enrolled at Rice University to play college baseball for the Rice Owls baseball team He was named Most Valuable Player of the 2011 Conference United States of America Baseball Tournament. In May 2012, he was named the Conference United States of America pitcher of the week.
The Minnesota Twins selected Duffey in the fifth round, with the 160th overall selection, of the 2012 MLB Draft.
He signed with the Twins and pitched for the Cedar Rapids Kernels in 2013, before receiving a promotion to the Fort Myers Miracle of the Class A-Advanced Florida State League. He began the 2014 season with Fort Myers, and was promoted to the New Britain Rock Cats of the Class Associate of Arts Eastern League, and then the Rochester Red Wings of the Class American Automobile Association International League.
The Twins invited Duffey to spring training as a non-roster player for 2015. He opened the season with the Chattanooga Lookouts of the Class Associate of Arts Southern League, and was promoted to Rochester in May.
With Tommy Milone going on the disabled list, the Twins promoted Duffey to the major leagues to make his major league debut on August 5, 2015.