Luis's contract was purchased from Lincoln of the American Association where he posted a 0.83 ERA in 21 appearances last season, while striking out 30 batters in only 21.2 innings. The 27-year-old Dominican Republic native began his career in the Houston Astros organization in 2006, and has also pitched in the Chicago White Sox and Boston Red Sox organizations. Luis ascended to Triple-A Pawtucket in 2010, after going 5-1 with a 2.72 ERA at Double-A Portland that season. The right-hander is 23-16 with a 3.88 ERA and 38 saves in six professional seasons, while averaging 11.4 strikeouts per nine innings.