An unusual bullpen session after the Dodgers' Wednesday workout didn't convince club officials that Saito's mechanics were consistent enough for him to pitch effectively.
Saito's spot on that roster was taken by left-handed reliever Hong-Chih Kuo, who has recovered enough from elbow problems of his own, despite pitching in only one game over the past month.
The remainder of the Dodgers roster, which had to be submitted by 10 a.m. ET Thursday, is the same as used in the NL Division Series.
Jonathan Broxton, who was overpowering while securing the Dodgers' clinching win over the Cubs in the NLDS on Saturday night, will be the closer for the NLCS. Rookie workhorse Cory Wade will be the primary setup man and Kuo the primary left-hander, limited to one inning.
Most likely, manager Joe Torre said he won't use Kuo on consecutive days because of his delicate left elbow, which has already been operated on four times before the latest trouble. His latest injury was to the triceps area above the elbow.
Kuo missed the NLDS with the Cubs, but he could be critical to the Dodgers' chances in this series. He was lights-out in three appearances against the Phillies this year, allowing one hit over five scoreless innings and notching his lone save of the season.
The Dodgers never used or needed a left-hander against the Cubs, but Kuo would be a key element in club tactics for this series because the Phillies have dangerous left-handed hitters in their lineup such as Ryan Howard and Chase Utley. Torre said he also expected Greg Maddux to be a factor because of his versatility.
Saito, 38, missed two months this season with a partially torn right elbow ligament and rehabilitated the injury without surgery. He returned to make six regular season appearances -- allowing three earned runs in 5 2/3 innings -- and was ineffective in his only NLDS appearance, allowing sharp base hits to each of the three Cubs batters he faced in Game 2.
"He never had a rehabilitation situation," Torre said. "He'll stay with us, throw a bullpen tomorrow and we'll make a decision whether to send him to Arizona (instructional league) for a day or two to pitch in a game if, with the World Series, we go on and are part of it."
Torre did not notify Saito of the decision before rosters were announced and said he apologized to the pitcher.
"I dropped the ball on this one," Torre said. "He didn't beat me up over it. I don't think he was surprised."
Torre speculated that Saito had been favoring his elbow and making mechanical adjustments all season.
"Even when he was getting people out," he said, "he wasn't the same guy. He found a way to pitch but was doing something different."
Saito was asked if he was disappointed with the decision and said it didn't matter how he felt, he was prepared to cheer his teammates from the bench.
"I don't disagree with the decision," he said. "I came back from the rehab and did everything I could, I gave everything I had and what I had wasn't enough to contribute to the team. I respect their decision."
Torre said he was more comfortable with Broxton as a closer after his overwhelming save Saturday night to clinch the NLDS.
"The pressure couldn't have been any more than it was," Torre said. "It doesn't matter what we see from here on out, the kid is qualified for that position. He handled that challenge with fanfare."
Broxton, Wade and Kuo will be joined in the bullpen by Joe Beimel, Chan Ho Park, Maddux, Clayton Kershaw and James McDonald. The starters for the first three games are Derek Lowe, Chad Billingsley and Hiroki Kuroda.
Position players are infielders James Loney, Blake DeWitt, Rafael Furcal, Casey Blake, Nomar Garciaparra, Jeff Kent, Angel Berroa and Pablo Ozuna; outfielders Manny Ramirez, Matt Kemp, Andre Ethier and Juan Pierre; and catchers Russell Martin and Danny Ardoin.
Ken Gurnick is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.