Ricketts will undergo surgery after fracturing his left ulna in a collision with San Jose midfielder Khari Stephenson.
After undergoing x-rays earlier on Monday, Ricketts is scheduled to undergo surgery on Tuesday. A four to six week absence to recover means Ricketts can feature again for the Galaxy at the end of July, at the earliest.
The loss of Ricketts will throw a wrench into Galaxy head coach Bruce Arena's plans, as he is already without the services of backup goalkeeper Josh Saunders, who was red carded in the 43rd minute of Saturday's game after replacing Ricketts. Midfielder Mike Magee filled in for the rest of the game, but for the Galaxy's July 4 match against Seattle Sounders FC, Arena will almost certainly go with 21-year-old Brian Perk, who has yet to make an MLS appearance in his career.