Hearn signed with the NPB's Hiroshima Carp on Saturday.
Hearn logged a hefty 11.40 ERA and 2.07 WHIP across 15 innings between Atlanta, Kansas City and Texas last season. His numbers improved to a 3.33 ERA and 1.56 WHIP in Triple-A, but he'll opt to play in Japan rather than wait for a minor-league offer from an MLB team.