Following a September call-up in 2003, Lowry enjoyed a very successful partial rookie year for the Giants in 2004, going 6-0, and finishing with a 3.82 ERA in fourteen starts.

The contract included a 2010 option for $6.25 million that would have been activated automatically if a certain number of starts, innings, and Cy Young Award vote placements was achieved.

In his first start of 2006, Lowry was removed from the game in the second inning due to an oblique strain,[3] forcing him to miss the first month of the season.

After having trouble throwing strikes early on in spring training, Lowry was diagnosed with exertional compartment syndrome[4] and had surgery on his left forearm on March 7.

[5] In May 2009 Lowry had a rib surgically removed to relieve the continued pain in his shoulder and neck associated with his recent diagnosis of thoracic outlet syndrome.

Lapa said the circulatory issue was the source of Lowry's forearm tightness in August 2007 and loss of control in spring training 2008, but that the Giants' medical staff failed to identify the problem.

[5] In a February 28, 2013 interview on Chronicle Live, Lowry stated, "It doesn't look like baseball is going to be in my future," and gave viewers a status update of his still-deteriorating health, his young family, his current career as an entrepreneur and ecology advocate, and his love for the San Francisco Giants and baseball in general.