Louisville point guard Peyton Siva has a severely sprained left ankle and is doubtful for Saturday’s game at Butler. The junior, whom coach Rick Pitino calls his best player, was injured Monday in practice. Pitino says Siva would be available only in an isolated situation and might not be ready when the Cardinals return home against Arkansas State on Nov. 22. Siva has averaged 10.5 points and 6 assists in No. 8 Louisville’s two games this season.