The Cardinals' pursuit of a lefthanded reliever to fortify their bullpen has intensified as the club has expressed interest in Baltimore closer George Sherrill, sources said. Sherrill, an All-Star who has 29 saves and a 3.89 ERA for the Orioles, has drawn increased attention from several teams, including the Milwaukee Brewers. The Cardinals have declined to discuss specific candidates. They have said lefthanded relief is one area they are looking to improve before the non-waiver trade deadline. Another possibility is Texas lefty reliever Eddie Guardado. The Rangers have interest in Class AA starter Jess Todd.