Wolf was with the Mariners in the spring and then the Diamondbacks to open the season. He didn't reach the majors with either team and was released by each. He was then picked up by the Marlins, where he did appear in six MLB games, going 1-3 with a 5.26 ERA and 1.52 WHIP before being released last week.
Wolf, 37, is 133-120 with a 4.21 ERA (100 ERA+) in his 15-year career.
The Orioles have Chris Tillman, Wei-Yin Chen, Ubaldo Jimenez, Bud Norris and Miguel Gonzalez in the rotation right now and just optioned talented youngster Kevin Gausman back to Triple-A, so Wolf won't be counted on as a major player. Depth never hurts, of course, and that's what he'll be counted on to provide.
News of Wolf's signing was first reported by the Baltimore Sun.