Matt Garza pitched one-hit ball for seven shutout innings and struck out 10, and Philadelphia finished with just two singles in Sunday's 5-1 loss to the Chicago Cubs.
The five-time defending NL East champion Phillies, playing without injured All-Stars Ryan Howard and Chase Utley, have scored two runs or less in 12 of 22 games this season.
"We didn't hit a ball hard," Manuel said. "We didn't get nothing going. I think Garza had a lot to do with it, but our hitting is inconsistent and we have to be more consistent."
"You have to hit some balls hard to win games. I feel like we're treading water. We have to play a lot better," he said.
Philadelphia looked to be snapping out of its season-long funk at the plate last week when it scored 20 runs in winning two out of three at Arizona. But the Phillies have generated just seven runs in losing two of three thus far in this four-game set.
"We definitely didn't get after him," Manuel said of Garza. "We showed we can look like a pretty good team, but today we were pretty inconsistent and fall back."
Minus their two key bats, Phillies hitters may be pressing some.
"At times everyone is trying too hard," said Laynce Nix, who went 0 for 3 while taking Howard's spot at first base. "We're all trying to get it doing and make a difference."
Garza (2-1) gave up a pop-fly single to Jimmy Rollins leading off the first and nothing more.
Rollins was back batting leadoff after being inserted into his usual spot in the order for the first time this season on Saturday. He struggled filling the No. 3 hole vacated by Utley and is hitting .222 on the season.
Garza retired 20 of the next 21 batters, with Juan Pierre's seventh-inning walk accounting for the only other baserunner.
"I just stuck to the game plan, keep them off-balance and try to get popups or groundballs," Garza said. "I was very comfortable out there. I wanted to go after them. They're a very aggressive team."
After reliever Rafael Dolis pitched a perfect eighth, Cubs closer Carlos Marmol was shaky in the ninth.
Marmol walked a pair and Hunter Pence's infield single with two outs loaded the bases. Marmol then walked Ty Wigginton to force home a run before getting Shane Victorino on a game-ending groundout.
Besides Rollins' single, the Phillies didn't have anything even close to a hit off Garza, who was lifted after 103 pitches.
"He was dominating," Cubs manager Dale Sveum said.
Joe Mather homered and Bryan LaHair doubled twice for the Cubs. Jeff Baker and Tony Campana each added two hits.
Mather's homer was the first by a Cubs outfielder this season.
"That's a crazy fact," Mather said.
Kyle Kendrick (0-2), making his second start in place of injured left-hander Cliff Lee, allowed two earned runs and five hits in six innings. He matched his career high with seven strikeouts.
"It's early. We've been through this before and the bats came through," Kendrick said.
The Cubs took a 1-0 lead in the second on Ian Stewart's groundout that scored LaHair. Chicago could have tallied more, with runners on second and third with one out, but Kendrick struck out Welington Castillo and Garza to escape further trouble.
Chicago tacked on a run in the third, thanks to the speed of Campana. After he singled, Campana went to second when Nix failed to catch Kendrick's throw on a pickoff attempt, then to third on Darwin Barney's groundout.
Campana scored on Starlin Castro's fly ball to medium right field, just beating the strong throw of Pence. Manuel came out to argue the safe call of plate umpire Bill Miller, but replays appeared to confirm the call was correct.
Mather's line-drive homer to left with two outs in the fourth put Chicago up 3-0.
Campana's speed showed up again in the eighth when he reached on an infield single, stole second went to third on a sacrifice bunt and scored on Castro's grounder that didn't even reach the infield dirt.
NOTES: The crowd of 45,550 was Phillies' 229th straight sellout, including postseason play. ... Wigginton went 0 for 3, ending his 13-game hitting streak.