Britton, 31, has pitched for his entire career as Zach. On Thursday, he tweeted that he is changing the last letter of his first name to Zack, after apparently finding out he was misspelling the name that appears on his birth certificate.
"Breaking news: I will be going by my legal name 'Zack' instead of my stage name 'Zach' ... everyone continue to breath normally," Britton tweeted, including the hashtags "#beenlivingalie" and "birthcirtfail."
The southpaw entered the league as a third round pick by the Baltimore Orioles in the 2006 MLB June Amateur Draft out of Weatherford High School in Weatherford, Texas. Britton made his big league debut in 2011.
The eight-year veteran played in Baltimore until being traded to the Yankees in July in exchange for Dillon Tate, Cody Carroll and Josh Rogers. He signed a three-year, $39 million contract with the American League East franchise in January.
Britton posted a 3.10 ERA and a 2-0 record with 21 games finished and seven saves in 41 appearances last season for the Orioles and Yankees. The two-time All-Star led the American League with 47 saves in 2016. He also led the American League with 48 games finished in 2015 and 63 games finished in 2016. Britton owns a 3.21 ERA and has 142 saves in 331 career appearances.