The San Diego Padres placed starting pitcher Clayton Richard on the 15-day disabled list with a left shoulder strain. The left-handed staple in the Padres' rotation was removed from Friday's start after just two pitches because of pain in the acromioclavicular joint of his left shoulder, near the collarbone. Richard received an injection on Saturday morning to calm the inflammation that caused him pain, starting after a June 16 start when he allowed one run in eight innings against Arizona.