LOS ANGELES -- The Los Angeles Dodgers placed right-hander Carlos Frias on the 15-day disabled list Sunday, retroactive to Tuesday. Frias has been dealing with discomfort in his lower back going all the way back to May, but it finally got to a point where the team did not want him to risk further injury by compensating for the back problem.

The move leaves the Dodgers without a starter for Monday. Manager Don Mattingly, however, hinted before Sunday's series finale against the New York Mets that the team has an idea who will make the start in place of Frias, but Mattingly didn't announce who it would be.

The most likely options are either reliever Juan Nicasio or a minor leaguer not currently on the team's 40-man roster. Whoever it is will also likely start next Saturday.

"We'll see what we do with our bullpen over the course of [Sunday's] game and then make a decision," Mattingly said. "We're not that concerned because there wasn't anything structurally [wrong] with his back. It was more of a tight muscle. It had gotten a lot better, but it hadn't gotten to the point where he could just throw and not be changing some things."

The concern was that Frias' back would alter his mechanics enough that it would affect his arm, leading to further problems.

Frias is 5-5 with a 4.39 ERA in 12 starts this season. Left-hander Daniel Coulombe was recalled to take Frias' roster spot.