MLB Single Season Leaders - Losses

1. Mike Maroth 21 (2003)
2. Omar Daal 19 (2000)
-- Bobby Jones 19 (2001)
-- Albie Lopez 19 (2001)
-- Jeremy Bonderman 19 (2003)
-- Darrell May 19 (2004)
7. Tanyon Sturtze 18 (2002)
-- Kip Wells 18 (2005)
-- Rodrigo Lopez 18 (2006)
-- Danny Cabrera 18 (2007)
11. Steve Parris 17 (2000)
-- Matt Clement 17 (2000)
-- Jose Mercedes 17 (2001)
-- Jimmy Haynes 17 (2001)
-- Jimmy Anderson 17 (2001)
-- Nate Cornejo 17 (2003)
-- Zack Greinke 17 (2005)
-- Jose Contreras 17 (2007)
-- Kip Wells 17 (2007)
-- Justin Verlander 17 (2008)
-- Barry Zito 17 (2008)
-- Aaron Harang 17 (2008)
-- Jeremy Guthrie 17 (2009)