/ STAFF WRITER
LOS ANGELES -- Carlos Frias labored through five innings Tuesday against the Arizona Diamondbacks due to lower back pain.
His next scheduled start, Monday against the Philadelphia Phillies, is unsure because of the same issue, Dodgers manager Don Mattingly indicated Saturday.
"We're still kind of talking about that," Mattingly said. "We haven't really made a decision on that."
Frias had an MRI on his back which revealed no structural damage, according to Mattingly, and he threw a bullpen session Saturday.