On the day Matt Kemp started his minor league rehabilitation assignment in Rancho Cucamonga, the Dodgers learned reliever Todd Coffey has been lost for the season and outfielder Andre Ethier appeared as if he could be headed to the 15-day disabled list. Coffey will undergo surgery to repair a partially torn ulnar collateral ligament in his elbow. He was moved to the 15-day disabled list Tuesday and replaced on the active roster by Shawn Tolleson, who had been sent down to triple-A Albuquerque a day earlier. Meanwhile, Ethier reported feeling something in his strained left rib cage while taking a swing in the batting cages. Ethier hasn't played since he was injured on June 27 in San Francisco, and Manager Don Mattingly said the Dodgers had to decide soon whether to put Ethier on the disabled list or continue playing a man short.