Jeffress (or as I spelled it at first "Jerreemy Jefffreeess") is a 25-year old from South Boston, Virginia (not the Boston we hate). He spent most of 2012 with Omaha of the AAA Pacific Coast League.
More to come--I assume.
UPDATE 1 (Minor Leaguer):
Jon Heyman reports that Jeffress was acquired for cash considerations.
UPDATE 2 (Minor Leaguer):
LHP Scott Maine DFAed to make room on the 40-man roster.