PHILADELPHIA -- It's only a couple of outings, but Edwin Diaz's performance in his previous two trips to the mound is exactly what the Mets were looking for when they acquired him this offseason.

Diaz threw a perfect inning against the Cubs on Wednesday and followed it up with another flawless frame in Friday's victory over the Phillies, prompting manager Mickey Callaway to call him "vintage Diaz" afterward. The righty forced seven swings and misses on 23 pitches across those two appearances, striking out five of the six batters he faced.

More encouraging than the raw numbers, however, is the movement Diaz has been getting on his pitches. He threw 12 sliders in those two games; opposing hitters swung and missed at five, while two others were called strikes and two were fouled off. Zero were put in play.

As for the fastball, on Friday, Diaz uncorked a 100.3-mph heater, his fastest pitch of the season. The only ball put in play against him in those two innings was a weak 65.3-mph groundout by Phillies slugger Rhys Hoskins.

"They’ve been working diligently every day," Callaway said of Diaz's work with pitching coach Phil Regan and bullpen coach Ricky Bones. "They go out early -- he and Phil and Ricky -- and throw off the mound every single day. He’s getting his slot back, his mechanics are under control and he’s getting his hand positioned on the ball where he needs it, where he’s going to get that movement."

That type of movement figures to play regardless of the situation, but it can't be ignored that Diaz's recent success has come in low-leverage spots. He entered with the Mets trailing, 10-6, in the eighth inning against the Cubs on Wednesday, then took the mound with a five-run lead in the eighth on Friday. He has only one save in his 10 August appearances.

"It would have been easy for him to just feel sorry for himself and give up on his season, because it’s been a rough one," Callaway said. "And he hasn’t done that."

Although Diaz has logged just the one save in August, part of that could be a product of the circumstances. Entering the month's final day, the Mets, as a team, had just four August saves, one of which came courtesy of Paul Sewald in the rain-shortened victory over the Indians on Aug. 22.

The Mets' last save in a full nine-inning game came from Seth Lugo on Aug. 17. Lugo had locked down a pair of saves in August and entered Saturday with four consecutive scoreless outings, striking out seven over six innings during that span.

As for whether Diaz has worked his way back into ninth-inning consideration, Callaway said he will continue to approach those decisions on a case-by-case basis for the time being.

"We’re just going to continue to pitch guys when it makes sense," Callaway said. "The way [Diaz is] pitching right now, I feel like he’s going to come in and get a strikeout in a big leverage situation. Based on both of those relievers’ availabilities, I think we can mix and match. He’s throwing the ball great, so we won’t hesitate to use him in any situation.”

News and notes

• Callaway said that Jeff McNeil's absence from Saturday's starting lineup was "part of the plan when we brought him back." McNeil had started each of New York's six games since returning from a strained left hamstring on Aug. 24.

• Brandon Nimmo (neck stiffness) was expected to start for Triple-A Syracuse for a second straight day on Saturday. Callaway said it's a "possibility" the club could activate Nimmo, who hasn't played a big league game since May 20, when rosters expand on Sunday.

• The Mets recalled right-hander Walker Lockett from Triple-A Syracuse prior to Saturday's game and optioned fellow righty Chris Mazza.