Vest's contract was selected by the Tigers on Wednesday.
Vest was informed Tuesday that he'll begin the season on the major-league roster, and the Tigers made the move official a day later as part of a large batch of transactions to finalize the roster. The 26-year-old made six relief appearances this spring and posted a 4.50 ERA, 9:3 K:BB and 1.33 WHIP in six innings.