Booser was added to the Rays' 40-man roster at the end of spring training after he had attended camp as a non-roster invitee, but he remained in the minors for the first two-plus months of the season. The 34-year-old southpaw is likely to work in middle relief for Tampa Bay after accruing a 1.80 ERA, 0.95 WHIP and 24:5 K:BB across 20 innings in 23 appearances for Durham.

Presumably, Booser had an opt-out in his minor-league contract, and the Rays added him to their 40-man roster to prevent the reliever from exercising that clause. Booser holds a 4.28 ERA and 78:35 K:BB over 73.2 innings at the big-league level.