On paper, opportunity should be knocking for the San Diego Padres. The Padres will welcome the struggling Colorado Rockies to town for five games in a span of four days beginning Monday night. San Diego, in second place in the National League West, has an uphill battle in trying to overcome a 12-game deficit to the Los Angeles Dodgers.But the Rockies, who have lost seven of 10 since the All-Star break,...