According to MLB Trade Rumors, the Tigers signed minor league pitcher Phil Dumatrait.
Dumatrait was non-tendered last week by the Pittsburgh Pirates, after the two sides couldn't agree on a contract. He missed large parts of the 2008 and 2009 seasons while recovering from shoulder surgery.
The 28-year-old left-hander pitched in 15 games as a reliever for the Pirates this year, compiling an 0-2 record and 6.92 ERA. He walked 11 batters in 13 innings. (Dumatrait also started 10 games in the minors this season.)
EDIT: ewild also posted this in a FanShot, adding that the Tigers signed first baseman Jason Stokes. Stokes hasn't played regularly since 2007.