The games will be played as a single-admission doubleheader at Citizens Bank Park. The opener starts a four-day, five-game series that ends Sunday in Williamsport, Pa., for the 2018 Little League Classic.
Corey Oswalt will start Game 1 for the Mets with Steven Matz taking the mound for Game 2. The Phillies (66-53) -- who are two games behind Atlanta in the National League East -- will use starters Ranger Suarez and Zach Eflin in the doubleheader, but they had not determined an order as of Wednesday night.
The Phillies' offense woke up on Wednesday night in a 7-4 win against the Red Sox, thanks in large part to the debut of catcher Wilson Ramos.
Ramos, who was acquired from Tampa Bay prior to the July 31 trade deadline, came off the disabled list after missing a month with a hamstring injury. He went 3-for-4 with three RBIs, two doubles and a triple in his first game with his new team. The Phillies had scored nine runs in their previous five games.
The Mets are 5-3 so far against the Phillies this season. They've won five of their last seven overall, including a 16-5 win over Baltimore on Wednesday night.
Matz (5-9, 4.35 ERA) will be returning from the disabled list for his start. He's coming off the worst outing of his big league career. In two-thirds of an inning, Matz allowed seven runs against the Washington Nationals in a game the Mets lost 25-4 on July 31.
Matz gave up just one run in five innings against the Phillies in his lone start against them this season. He is 0-1 with a 2.53 ERA and 1.406 WHIP in two starts against Philadelphia in his career.
Oswalt (1-2, 5.03) will be making his eighth major league start for the Mets, and the 24-year-old rookie has allowed three runs or fewer in each of his last six outings. Oswalt has a 3.94 ERA in that stretch, which includes a July 9 start when he gave up three runs on just one hit against the Phillies.
Oswalt, a righty, went six innings and allowed three runs on six hits against the Miami Marlins in his last outing on Saturday.
"I thought he was good," Mets manager Mickey Callaway told MLB.com of Oswalt after the start. "Good deception. He throws the ball over the plate and keeps his pitch count down so he's going to be able to pitch deep into the game if he's that efficient every time. He threw a really nice ballgame."
The Phillies will also be using a rookie starter during the doubleheader in Suarez (1-0, 7.20). It will be the second major league start for the 22-year-old. He threw five innings and allowed four runs against the Cincinnati Reds on July 26, picking up a win in a 9-4 Phillies victory.
Eflin (8-4, 3.57), meanwhile, will be rejoining the Phillies after he was optioned to Triple-A Lehigh Valley after his last start to create an extra roster spot.
Eflin has been part of the Phillies' rotation since the beginning of May. The Phillies have lost four of his last five starts, though, including a game against the San Diego Padres last Friday. Eflin went six innings in that contest, striking out eight and surrendering just two runs, but the Phillies were shut out.
Eflin is 0-2 with a 4.64 ERA and 1.172 WHIP in four career starts against the Mets. In his one start against the Mets this season, Elfin gave up three runs and five hits in five innings, but did not get a decision in the Mets' 4-3 win in one game of the doubleheader on July 9.