Mired in a 3-for-29 slump, Kemp was scratched from Saturday's lineup and is scheduled to undergo a contrast MRI on his left shoulder. He also received a cortisone injection in the shoulder.
Kemp said he felt pain in his shoulder every time he swung and missed. He realized it was sapping some of his power when he hit a deep drive at Dodger Stadium last week that Cameron Maybin made a leaping catch on at the wall.
"I didn't have that extra oomph on the ball," Kemp said.
Dodgers manager Don Mattingly said Kemp will be out until at least Tuesday.
The Dodgers are 4 ½ games behind the San Francisco in the NL West after a 3-2 win against the Giants on Saturday. Kemp injured his shoulder colliding violently with the outfield wall in Colorado on Aug. 28. He missed just two games after the collision.
"I appreciate him wanting to play, wanting to be tough and go out there, but at some point you've got to be honest and say either I can help the team or I can't help the team," Mattingly said. "If it's hurting him to swing the bat and if he's not able to do some things, it doesn't do us any good for him to be out there."
Kemp, last season's runner-up to Ryan Braun for the NL MVP, is batting .315 with 18 home runs and 56 RBIs in 85 games. In the game at Colorado, he ran into the wall trying to track down a triple by Josh Rutledge. Kemp turned into the padding while running full speed and fell backward onto the warning track. He stayed down for several minutes as team trainers checked him over. He got up, took a drink of water and initially stayed in the game.
Kemp went 0 for 5 with an RBI and a strikeout on Friday night. He already spent two stints on the disabled list this season before the All-Star break with a strained left hamstring. Kemp is hitting .290 (58 for 200) with six home runs and 28 RBIs in 49 games since coming off the DL.
The Dodgers have greater offensive depth since midseason trades that landed them Hanley Ramirez and Adrian Gonzalez. But they have gone just 20-21 since the Ramirez trade and 5-8 since acquiring Gonzalez.
"We haven't been doing it with Matt, which doesn't mean we're going to do it without him, but I think we're more than capable of winning without one of those guys," Mattingly said.
"Just go out and play. No excuses," right fielder Andre Ethier said of playing without Kemp. "You can't have any excuses in this game."
Infielder Adam Kennedy is likely done for the year after injuring his groin during Friday's 5-2 loss. Mattingly said Kennedy was hurt when the third baseman tried to barehand Hunter Pence's infield bouncer for an RBI single in the sixth inning.
"He felt something pop," Mattingly said. "I haven't heard anything definitive about whether he's going to play again or not, but it doesn't sound very good."
Information from The Associated Press was used in this report.