(Photo credit: Brad Penner-USA TODAY Sports)

A doubleheader sweep Saturday continued to give the New York Mets some things to build upon for next season.

The Mets (74-86) will look to complete a series sweep on Sunday when they host the Philadelphia Phillies (89-72) in the regular-season finale.

Right-hander Jose Butto (1-3, 3.75 ERA) isslated to start for the Mets against left-hander Matt Strahm (9-5, 3.32). Strahm is expected to serve as the opener ahead of right-hander Nick Nelson, who will make his first regular-season appearance since last Oct. 5.

The Mets captured both ends of a doubleheader on Saturday. Tylor Megill carried a shutout into the eighth inning of a 4-3 win in the opener and Francisco Alvarez homered twice and finished with six RBIs in an 11-4 victory in the nightcap.

With the wins, the Mets improved to 13-13 during a September in which they've received encouraging outings from a piece-meal rotation.

Megill, Butto, Kodai Senga, David Peterson, Jose Quintana and Joey Lucchesi have combined to post a 3.20 ERA in 27 starts - including Thursday night's game against the Miami Marlins, which was suspended due to rain in the ninth inning with the Mets trailing 2-1. That game will be resumed Monday if it impacts the Marlins' playoff seeding.

Only Senga has spent the entire season on the active roster for the Mets, who expected Cy Young Award winners Max Scherzer and Justin Verlander to serve as co-aces but traded both pitchers in July. Quintana didn't debut until July 20 due to a fractured rib while Megill, Butto, Peterson and Lucchesi combined for 46 starts at Triple-A Syracuse.

"They've done things to leave a good taste in everybody/s mouth," Mets manager Buck Showalter said. "They're ours, whether it's here or Syracuse next year. I think the depth of our rotation is going to be in good shape next year."

The Phillies are focused only on being in good shape on Tuesday, when they'll begin the playoffs as the top National League wild-card representative. Philadelphia will host either the Marlins (84-76) or Arizona Diamondbacks (84-77) in a best-of-three series.

The Phillies used Saturday's doubleheader to begin getting their pitching in order for the playoffs. Taijuan Walker, the likely No. 3 starter next week, gave up four runs in the first two innings before lasting seven frames in the opener.

A quartet of pitchers expected to be on the postseason roster -- Orion Kerkering, Jose Alvarado, Craig Kimbrel and Cristopher Sanchez -- got the final 12 outs of the second game after rookie Michael Plassmeyer allowed up 10 runs (nine earned) and three homers in 3 2/3 innings.

"We used exactly the people that we needed to use today," Phillies manager Rob Thomson said. "It all worked out."

The Phillies also got good news about shortstop Trea Turner, who was diagnosed with a left elbow contusion after Reed Garrett plunked him in the seventh inning. Turner won't play Sunday but is expected to be fine for Tuesday.

Butto will face the Phillies for the second straight start. He took the loss last Sunday after allowing four runs over four innings. The 25-year-old is 0-1 with a 12.38 ERA in two career starts against Philadelphia.

Nelson, who suffered a left hamstring injury in spring training, went 7-3 with a 4.35 ERA in 20 starts for Triple-A Lehigh Valley. He is 0-0 with an 8.10 ERA in seven relief appearances against the Mets.