Whatever ails the Phillies, they need to fix it fast if they want to return the playoffs for the second straight season.
"We're just pressing so hard to make up ground in one game," said Myers, who took the loss.
Philadelphia fell three games behind the NL East-leading New York Mets, who played later Wednesday night.
The Phillies also dropped four games behind Milwaukee in the wild-card race. The Phillies hopes for a postseason return could get a boost -- or be thwarted -- when they open a four-game series with the Brewers on Thursday at Citizens Bank Park.
"It's going to be an exciting four games here, but we've got to start winning some games," Chase Utley said.
At this point last season, the Phillies were six games behind the Mets and ended up winning the division on the final day. But there's a crucial difference between the NL East champions and this year's team.
"I think the difference is, last year we were hot," Manuel said. "We had enough pitching to get through. We were energetic. We had life. We really got after it."
There was little fun for the Phillies on Wednesday.
Reliever J.C. Romero and catcher Chris Coste appeared aggravated with each other on the mound after the lefty allowed a two-run double in the ninth. Jimmy Rollins shot a look at center fielder Shane Victorino after a lazy throw into the second base on the same play.
"We let it get away from us there at the end," Manuel said.
"Nobody's giving up," said Nolasco. "We're not just coming in here and finishing out the season.
Nolasco (14-7) struck out Howard, Pat Burrell and Victorino in the fourth, and even had an RBI single. He hasn't allowed more than three runs in any of his last nine starts and is 4-1 over that span.
Ryan Howard hit his major league-leading 42nd homer for the Phillies. The Phillies didn't have a hit after the fifth inning.
"It's fun coming in here in September knowing you still have a mathematical chance," said Marlins manager Fredi Gonzalez.
Myers (9-11) had another solid outing -- nine strikeouts, four runs in 7 1/3 innings -- but lost for only the second time in 10 starts since he was recalled from the minor leagues on July 20.
Myers went from opening day ace to the minor leagues and back to arguably their second-half MVP as the defending NL East champs make another late-season playoff push. He retired 10 straight until Gonzalez touched him with a leadoff single in the eighth and the game tied at 3.
After another single put runners on the corners, Manuel saw enough of his tiring right-hander.
Willingham ripped a ground-rule double down the third-base line for a 4-3 lead. The ball was touched by a fan, likely preventing pinch-runner Robert Andino from scoring. After an intentional walk, Chad Durbin retired Paul Lo Duca on a double play to end the inning.
Myers said he'll take the ball Sunday on three days rest against the Brewers, if needed.
"We were a little more relaxed last year," said Myers, who was their closer last year.
Nolasco struck out the side in the fourth and was staked to a 3-1 lead when he ran into trouble. Coste had an RBI double to center that made it 3-2. Coste, though, was stuck on third after a sacrifice bunt and Rollins popped up. Jayson Werth poked an RBI single to left that tied the score.
Myers gave the bullpen a breather a day after six pitchers combined to go 7 1/3 innings in a 10-8 loss. He started strong, striking out four of five batters he faced in one span, then allowed a two-run shot to Gonzalez in the third. Gonzalez's eighth homer of the year gave the Marlins a 2-1 lead.
Myers allowed Dallas McPherson's leadoff double in the fourth and the Marlins third baseman scored on Nolasco's RBI single to left for a 3-1 lead.
Howard put the Phillies ahead 1-0 in the second when his 42nd homer of the season smacked off the scoreboard in right.
- The Phillies will start LHP Jamie Moyer (13-7, 3.64 ERA) on three days rest against Milwaukee on Thursday. Moyer pitched seven scoreless innings Sunday against the Mets in the first game of a doubleheader.
- The Phillies activated OF Geoff Jenkins from the 15-day disabled list. Jenkins was out for 2 1/2 weeks with a strained right hip flexor.
- Phillies INF Andy Tracy is out for the rest of the season with a broken hand. Tracy, a utility infielder with only two at-bats this season, was hit on the left hand by a line drive during batting practice.