DiFelice started his professional career as a part of the
Colorado Rockies organization in 1998. He played his first season for their Class A (Short Season) affiliate, the
Portland Rockies. In 1999, DiFelice advanced to the Class A-Advanced
Salem Avalanche. In 2000, he played for the Double-A
Carolina Mudcats. DiFelice also played part of the 2001 season for Carolina, while also pitching for the
Triple-A Colorado Springs Sky Sox. In 2002, he was sent back down to the Class A (Short Season)
Tri-City Dust Devils and Salem. In 2003, he played for the Rockies' new Double-A affiliate, the
Tulsa Drillers. In 2004, DiFelice switched to the
Baltimore Orioles organization, playing for their
Triple-A Ottawa Lynx. In 2005, DiFelice pitched for the
Washington Nationals with their Triple-A
New Orleans Zephyrs and the independent
Atlantic League's
Somerset Patriots. He stayed with the Atlantic League for 2006, playing for the
Camden Riversharks. DiFelice returned to affiliated baseball in 2007, playing for the
Milwaukee Brewers' Double-A
Huntsville Stars, and then their Triple-A
Nashville Sounds. After his first ten professional seasons, DiFelice had a record of 77–57, with an
ERA of 3.53, and had recorded 951
strikeouts. ==Major league career==