Andrew Cashner and Carlos Quentin took positive steps Tuesday toward manning spots on the Opening Day roster. But Logan Forsythe appears to be headed for the disabled list rather than subbing for Chase Headley at the start of the season. The plantar fasciitis in Forsythe’s right foot flared up during a 3 ½-inning outing against San Francisco in an exhibition won 4-2 by the Giants. “It’s not so good,” Padres manager Bud Black said when asked about Forsythe, who was playing in his first major league exhibition since the diagnosis of plantar fasciitis was made on March 7. “He’s not going to be able to play in a couple days, no way,” said Black. When asked about the disabled list, the manager said: “I suspect with the amount of pain he is in, we’re headed in that direction.” Forsythe was 0-for-3 and twice drove the ball to the outfield. He made one play on a grounder during three innings in the field. “But the pain got worse the more he was on his feet,” said Black. “It’s not looking too good in the short term.” Forsythe said earlier this week that he wanted to give the plantar fasciitis “a solid test this week.” But he said if the pain worsened, he would likely have to have a second injection in his right foot then have the foot placed back in the protective boot “for a longer period of time.”