First impressions matter, even if the opening day of USC football spring practice was “just one day, with 14 more to go,” in the words of assistant head coach Steve Sarkisian. The 500 or so fans who showed up for the first workout saw a trio of quarterbacks rotate in with the first team. The top two, Mark Sanchez and Mitch Mustain, didn’t allow much distance to come between them and seemed pleased afterward, as did their coaches.<!– Image starts here –>