Manager Don Mattingly said Billingsley has been battling the pain for a while. Billingsley said he doesn't know exactly when the pain started but said it has been a couple of weeks.
"It feels like any other type of soreness," he said. "The arm never feels 100 percent all the time."
He had a regular bullpen session on Friday that wasn't sharp, and after a shortened "touch-and-feel" session Saturday told trainer Sue Falsone that his elbow was "barky." Mattingly got the information during Saturday night's game.
"My only issue about it is not letting anybody know so we could be paying attention to this thing," said Mattingly, who hopes to find out the MRI results by the end of the day. "Sue and those guys go to school a long time and they are pretty smart. They can't really help you if you don't talk to them."
"They are not mind readers," he added.
Billingsley said once he starts throwing and it loosens up that he feels fine. He is hopeful he won't be out for long.
"I thought I could have gone today, but they wanted to be cautious and not make it more worse of a situation than it is," he said.
Billingsley learned he was scratched on a phone call from Capuano late Saturday night. Mattingly said he was hopeful the MRI would reveal only tendinitis or something minor that would require Billingsley to miss a start but not be sent to the disabled list. The Dodgers already were looking to acquire a starting pitcher by the end of the month, with Ryan Dempster and Matt Garza of the Cubs, Zack Greinke of the Brewers and Cole Hamels of the Phillies among their targets.
Nathan Eovaldi will move up a day in the rotation to pitch Monday in the opener at home against the Phillies, but Tuesday night's starter remains to be determined. The Dodgers have no likely Minor League candidate on the 40-man roster beyond Stephen Fife, a right-hander who is 7-5 in 18 starts at Triple-A Albuquerque. Pitching coach Rick Honeycutt said there is "no way" Clayton Kershaw will be moved up a day to pitch on three days' rest.
Mattingly said he would sometimes keep pain a secret when he was a player and understands it is part of the game since athletes like to give off a tough exterior and play through pain. However, he was visibly upset with his starter for not saying anything sooner.
"We would have liked to have known this a littler earlier," said Mattingly, who talked to Billingsley about the situation. "We could have set up the rotation differently, try to bounce in a start earlier when we had a day off and just protect him that way. But when guys don't talk, you can't protect them."
He considered moving Eovaldi ahead of Capuano in the rotation to pitch Sunday, but the rookie was unavailable after pitching a bullpen session on Saturday. Capuano threw a bullpen session a couple days ago and Mattingly said the 33-year-old had no hesitations sliding up a day.
Billingsley is riding a five-game losing streak and hasn't lasted more than six innings in a game since June 10. The righty is 4-9 with a 4.30 ERA in 18 starts this season.