PITTSBURGH — Edwin Díaz’s arsenal during his Mets tenure has consisted strictly of fastball/slider, but earlier this week, he tried something new. 

The Mets closer unleashed a changeup in his Monday appearance against the Braves.

It’s a pitch Díaz has toyed with while playing catch but hadn’t developed enough confidence in to use during a game. 

His verdict? The pitch still needs work. 

Under ideal circumstances, Díaz would have the ability to deliver his changeup in the low 90s, creating a noticeable speed contrast with his fastball. Yet, during a recent match, Díaz’s changeup registered at 95 mph, indicating only a slight velocity discrepancy from his fastball. This lack of significant speed difference diminishes the pitch’s effectiveness.

“I wanted to see how it would look in a game,” Díaz said Saturday before the Mets’ 9-2 loss to the Pirates at PNC Park in which the Mets players called a team meeting after the ugly defeat. “It didn’t look good, because I threw it 100 percent. When I throw it playing catch, I throw it maybe 60 percent so the movement is way better. I have got to find a way to decrease the velocity a little bit more.” 

Díaz, who did not pitch in Saturday’s loss, throws his fastball 51.8 percent of the time, according to Statcast. He’s utilized his slider on 48 percent of occasions, with the one changeup mixed in. 

Why add the changeup? 

“It will make [hitters] think more,” Díaz said. “But I have got to make sure I have a good changeup. If I don’t feel it’s good enough, I will stick with my other two pitches.” 

It’s hard to argue against what has worked to this point for the right-hander, who entered Saturday with a 1.99 ERA in 32 appearances for the Mets this season.

He was also 16-for-17 in save opportunities. 

Díaz’s big first half has positioned him as a possibility to represent the team in the All-Star Game. His lone selection for the Mets came in 2022 — but he didn’t appear in the game. 

Pete Alonso, Francisco Lindor and Juan Soto are the Mets’ finalists for the NL roster, among position players. 

“It would be good to be in that group,” Díaz said. “As a player, you always want to be asked. That is one goal I have before the start of the season, so if I make it, I will be really happy.” 

Díaz had a slow start to the season, pitching to a 4.50 ERA in April. But he’s been a different pitcher over the past two months — entering Saturday he had allowed only one earned run over his previous 20 appearances for a 0.41 ERA. 

“My first month wasn’t that good, but after that, I started feeling better,” Díaz said. “I am commanding my spots really good. I walked too many people in that first month and I think that was the main thing, throwing strikes.” 

Díaz is hesitant to say he’s back to his 2022 level. His numbers that season included a 1.31 ERA and 0.90 WHIP with a strikeout rate of 50.2 percent. Díaz’s strikeout rate this season is 36.8 percent. 

Even so, Díaz isn’t complaining. 

“My strikeout rate is still really good and I feel good how I am throwing the ball right now,” Díaz said. “I am attacking the hitters. I feel like I am having a real good season.” 

His usage has increased in the last week — he appeared three times in four games against the Braves — after a stretch in which the Mets weren’t in enough high-leverage situations to warrant using him. 

Manager Carlos Mendoza has also been careful to monitor Díaz’s workload. 

“I feel great physically,” Díaz said. “I know my body better so I don’t have to be on the mound every three or four days. If we don’t have a save situation I can throw a bullpen and be ready when they need me.”