Mattingly also sat third baseman Juan Uribe, starting Juan Rivera at first base, Bobby Abreu in left field and Elian Herrera at third base.
"Really, I'm playing the guys I feel give us the best at-bats," said Mattingly. "Right now, it's tough. Juan is struggling, too. Elian swung the bat good last night. I have a little less defense with this lineup, but we're having trouble scoring runs and I've got to put the best offense out there. Right now, I've got to try to find ways to score.
"I've tried to tell James what's going on, just be honest. It's tough, but I've got to find production. Between James and Juan at the corners, two power positions, we've got two homers and 33 [RBIs]. We're still in a good position, but we won't be able to sustain it. I'm not trying to be [nasty] to anybody. It's not personal, but I've got to find production and it's not happening. You've got to produce. This is the big leagues, not instructional league or coming through the Minors."
Loney is eligible for free agency after this season, while Uribe is in the second year of a three-year contract. Nonetheless, it's no secret the Dodgers are looking on the trade market for corner infielders who can hit.
On the current trip, Loney is 0-for-14 and Uribe is 1-for-18. However, Herrera is 2-for-24 on the trip (0-for-15 most recently), A.J. Ellis is 2-for-16 and Abreu is 2-for-19.