All-Star catcher Buster Posey has returned to the San Francisco Giants' lineup after missing two games with discomfort in his left knee. Posey started Friday night against the Atlanta Braves. Giants manager Gabe Kapler also said Friday that catcher Curt Casali, the fill-in starter for Posey who left Thursday night's 3-2 win at New York due to dizziness, was available off the bench.