He went on the disabled list Saturday with inflammation in his elbow, his second stint on the DL for the injury this season.
"This is the next step to see if he's going to be able to pitch again this year," Dodgers manager Don Mattingly said. "Then we'll go from there."
Platelet-rich plasma -- or PRP -- is an emerging treatment to help in the healing of tendons or ligaments without resorting to surgery. The Dodgers haven't ruled out the possibility that Billingsley will require Tommy John surgery, a procedure that would cost him most of the 2013 season as well.
Kasten told the Times that his concern is "not based on medical evidence." He also told the newspaper the Dodgers' ongoing search for another starting pitcher is not related to Billingsley's elbow injury.
"There has never been a team in the history of baseball that has not been looking for pitching," Kasten told the Times.
Dodgers general manager Ned Colletti said the talent pool that has either cleared waivers or remains on waivers is "very thin right now." Any player acquired after Friday would not be eligible for postseason play.
"We'll see if something turns up between now and tomorrow night, but right now there's nothing," Colletti said. "It's always possible, but it wouldn't be anything earth-shattering if it happens."
Billingsley is 10-9 with a 3.55 ERA this season. The former All-Star missed two weeks in July because of an elbow injury but has been sensational over his last seven starts, going 6-0 with a 1.80 ERA during that stretch.