49ers WR Michael Crabtree (neck strain) did not practice Thursday and spent time working with trainers on a side field. Coach Mike Singletary continues to say his injury isn't serious, but he doesn't plan to rush Crabtree back into action. "We’re going to take it one day at a time," Singletary said. "This is preseason." Singletary wasn't sure if Crabtree would play in the second preseason game against the Vikings on Sunday. “I don’t know, it’s just a day to day situation,†Singletary said. Source: CBS Sports