Left-hander Barry Zito is returning to the Oakland Athletics with a minor contract that includes an invitation to major league spring training, two people with knowledge of the agreement said Tuesday. The deal was first reported by the San Francisco Chronicle. He was taken by Oakland in the first round of the 1999 amateur draft and began his major league career with the A's the following year. He signed a $126 million, seven-year contract before the 2007 season to join the San Francisco Giants but had a largely disappointing stint across the bay.