 He began his minor league career in Class A for the <unk> Giants . After an unsuccessful year at the plate the Giants tried to convert Nathan into a pitcher , but he refused and left to return to Stony Brook for a year , graduating with a degree in business management . He gave more thought to his future in baseball , however , and after graduation decided to return to the Giants organization and developed into a standout pitching prospect . After a season with the Salem @-@ <unk> <unk> , he pitched for both the A and AA levels for ( the San Jose Giants and Shreveport Captains ) in 1998 as a starter . During his tenure with San Jose he started 22 games with an ERA of 3 @.@ 32 and 118 strikeouts , leading the Class A Giants to the California League championship . Promoted to AA Shreveport in 1999 , he pitched in only two games before being promoted to the parent club in 1999 . 
