Doocy, who is 27th on the career riding list with 4,586 victories, was injured when Chukkaluk, a first-time starter, reared up approaching the starting gate prior to the first race. The filly fell backwards and on top of Doocy.
"I couldn't get away from her," Doocy said. "She landed on me, and I had a leg on each side of her. Something has to give, and it's usually you.
"I'll be out the rest of the meet, I'm sure. I'll probably wait until Hot Springs opens (in January at Oaklawn Park)."
The first set of x-rays showed no fracture, but Doocy stayed overnight because he felt something was wrong. The next day, the separation was discovered. He also faces possible surgery to repair his urethra.
"It could have been a lot worse," he said. "I could have been crippled. The way I look at it, I've been pretty fortunate with injuries. This is probably one of the most painful. I'll be back."
Doocy set a Prairie Meadows record by winning 132 races in 2004 and was again the leading rider at this year's spring meet. At 49, he said he'd like to reach the 5,000-win mark before he retires, and isn't thinking about life after riding.
"You think about it, but I'm not really thinking about it," he said. "I'm not done yet. I'm enjoying it."
As Doocy went down with an injury, Terry Thompson returned. Thompson hadn't ridden since April 30. Like Doocy, he was hurt when a horse reared and flipped onto him, breaking his pelvis.
With Doocy out, Thompson moved up his comeback by one day and rode two horses Friday scheduled for Doocy. He finished third with Fear de Bay and won with Innisbrook.
"This is the first time that I've come off the injury and won the first night," he said. "I hope it's a good omen."
Thompson said he'll ride about two horses a night for the first week and hopes to build up to a full card by the third or fourth week.
"Fitness-wise, I'd say I'm about 75 percent," Thompson said. "That just comes with riding races."