Update: Chip Kelly has a quarterback problem. His starter, Michael Vick, can't stay on the field. His backup Nick Foles struggled in his last start before suffering a concussion. The team's third quarterback, Matt Barkley, looks like a rookie.
Kelly admits he's "concerned" about Vick, who will undergo more tests Monday.
"I felt the same feeling that I had the first time," Vick said in reference to his first hamstring injury, which kept him out two weeks. "I don't think it's as bad, but it did pop again. ... I've never had a hamstring injury this bad."