 The San Francisco Giants signed Richardson after they took him in the 35th round of the 2005 Draft.In 2005 he batted .321/.465 (4th in the league)/.378 with 45 runs (tied for the league lead), 44 walks (leading the league), 7 sacrifice hits (tied for 2nd in the league), 8 hit by pitch (tied for 5th in the league) and 40 stolen bases (leading the league) in 193 at bats for the Rookie AZL Giants, and was a 2005 Post-Season Arizona League All Star.In 2006 he batted .292/.381/.366 with 7 sacrifice hits (tied for 7th in the league) and 66 stolen bases (3rd) in 418 at bats for the Augusta GreenJackets of the Class A California League.