Ted Lilly and Matt Guerrier were scheduled to continue their rehab assignments by pitching tomorrow and Wednesday for Single-A Rancho Cucamonga.

Lilly’s outing is in jeopardy, however, after manager Don Mattingly said the left-handed pitcher “didn’t look real good” after a workout Sunday morning.

“I’m thinking Teddy’s not going to make his start,” Mattingly said. “He felt something … I think in his back or something.”

Lilly’s rehabilitation has been up and down. Initially bothered by elbow stiffness, he didn’t face live hitters in a game between May 23 and a July 29 rehab start for Single-A Rancho Cucamonga. After a brief setback, Lilly tossed one inning for the Quakes on Aug. 14 and two more innings two days later.

He hasn’t faced live hitting since, so if Lilly is able to return to the Dodgers before the end of the season, it will be out of the bullpen.

Chad Billingsley was placed on the disabled list Saturday with an inflamed right elbow. He’s eligible to return from the disabled list Sept. 9 but Mattingly doesn’t know if the right-hander will be able to return on time.

“It’s going to be until next week before he gets another MRI,” he said. “Then we’ll know a lot more. They’ll have to wait for the swelling to go down to get a better view.”

Billingsley’s first MRI “didn’t show us enough that it’s not clear-cut anything,” Mattingly said. “Not really bad, not really good. At this point, I don’t know.”

If Billingsley returns this season, Mattingly thinks the right-hander will have enough time to build up enough innings to rejoin the starting rotation. In that case, the Dodgers will have six starters to choose from –Billingsley, Clayton Kershaw, Chris Capuano, Joe Blanton, Josh Beckett and Aaron Harang. The manager has not revealed how he plans to use them.