The Tucson Sidewinders are like an auto parts store that helps keep the Arizona Diamondbacks' high-end luxury vehicle running smoothly. Both sides understand the role. A Triple-A club is there to serve the major-league team. The Diamondbacks and Sidewinders have had a working agreement since 1998, when the old Tucson Toros franchise switched from an affiliation with the Milwaukee Brewers, and moved to TEP Tucson Electric Park from Hi Corbett Field.