(Sports Network) - The Philadelphia Phillies will try to stop a three-game slide before the playoffs begin next week, as they close out their series Sunday versus the Florida Marlins at Citizens Bank Park.

Philadelphia has dropped three in a row since clinching its third straight National League East crown, and the skid has prevented the club from earning the best record in the Senior Circuit and homefield advantage throughout the NL playoffs. The Phillies, who will have the home edge for their division series versus Colorado, dropped a 4-3 decision on Saturday to the Marlins in the second portion of this three-game series.

Cole Hamels fell to 10-11 after giving up three runs and three hits through the first three innings, while Ryan Howard and Jayson Werth both went deep in a losing cause. Howard hit his 45th home run of the season and Werth connected on his 36th blast of 2009.

"Guys were having different approaches than they normally do," said Hamels, last year's World Series MVP. "Every pitch I threw for a strike, they hit. All of a sudden you're asking yourself what happened."

NL Rookie of the Year candidate J.A. Happ gets the nod for the Phils today and he is 12-4 with a 2.95 earned run average in 34 games (22 starts) this season. Happ beat Houston the previous time out on September 29 in a 7-4 victory, as he surrendered four runs -- three earned -- and nine hits in 5 2/3 innings.

Happ, who is 5-2 at home this season, topped the Marlins back on July 19 at Land Shark Stadium with seven shutout innings of five-hit ball in a 5-0 win. The left-hander is 1-0 with a 5.02 ERA in four career games (1 start) against Florida.

The Marlins haven't made the playoffs since winning their second World Series title in 2003, and will try to end this season on a positive note. They have recorded four consecutive victories and got RBIs from Chris Coghlan, Hanley Ramirez, Jorge Cantu and Dan Uggla.

Anibal Sanchez posted the win with seven innings of one-run ball and Leo Nunez closed the door in the ninth for his 26th save.

"We got three runs early in this ballpark. That was really the key," said Marlins manager Fredi Gonzalez. "With that lineup out there, they can put up a big number anytime. I thought Sanchez was excellent to hold them off like that."

Josh Johnson will close out his career year on Sunday for the Marlins and is 15-5 with a 3.08 ERA in a career-high 32 starts. Johnson owns a 2-1 record in his last five starts, but did not record a decision on Tuesday in a 5-4 win at Atlanta. He allowed only one run and three hits in five frames.

In his previous start before that, Johnson was reached for four runs in five innings of a 9-3 loss to Philadelphia on September 22. He is 1-1 in three matchups with the Phillies this season and 4-2 with a 3.75 ERA in 10 career games, eight of which have been starts.

Florida leads the 2009 season series with Philadelphia by a 9-8 margin.