Busenitz joined the Reds as a non-roster invitee Tuesday.
Busenitz owns a 4.58 ERA in 57 career major-league innings, the last of which came in 2018. He's spent the last four years with the Rakuten Eagles in Japan, where he's cruised to a 2.83 ERA in 155.2 innings. The 32-year-old righty will try to earn a bullpen spot in camp.