Steve Kroner subbing for Susan Slusser for the finale of a three-game series between Kansas City and the A’s at the Coliseum: After missing the previous two games because of leg tightness, center fielder Billy Burns (in the cage, above) is back in the leadoff spot for Sunday’s game against Kansas City and right-hander Jeremy Guthrie. Bob Melvin didn’t say Burns is 100 percent healthy, but the A’s manager is sure Burns can help the club. “He’s back in the lineup today. He’s good enough to play,” Melvin said. “Everybody goes through periods where they have some bumps and bruises, but two days off should make him significantly better.” Burns