Over the past month, Alejandro De Aza has completely turned his season around. He has been unrecognizable in July hitting .333/.484/.500 with a double, a home run, and an RBI. With De Aza being and useful and productive player, it seems like anything is possible including but not limited to Antonio Bastardo becoming a competent part of the Mets bullpen. Yes, even that. And it has happened.

In Bastardo’s has 10 appearances, he has pitched 12 effective innings. Over this stretch, he has a 2.25 ERA and a 0.833 WHIP. Batters are only hitting .205/.222/.341 against him. This is a completely different pitcher than the one who pitched to a 5.46 ERA and a 1.618 WHIP over his first 29 appearances that saw batters hit a whopping .261/.372/.443 off of him. He has gone from a guy Terry Collins justifiably buried in the bullpen necessitating the Mets to seek out a reliever on the trade market to a potentially valuable piece in the bullpen. What has happened?

As strange as this may sound for a pitcher on the Mets, Bastardo has benefitted from throwing his slider more frequently. Coming into this season, Bastardo had used his slider 31% of the time, and it proved to be a plus pitch for him. Batters didn’t make much contact off the pitch swinging and missing 44.46% of the time. When a batter was able to put the bat on Bastardo’s slider, it usually resulted in weak contact with the batters having a .168 batting average and isolated power of .091. For whatever reason, Bastardo has shied away from this pitch in the beginning of 2016.

To start the season, Bastardo’s slider usage rate dropped from 31% to 24%. Instead, Bastardo began to throw more changeups, which is a very bad idea. Over his career, batters tee off on Bastardo’s changeup hitting .375 off the pitche with a .609 slugging percentage. Essentially, every batter turns into Babe Ruth when they get a chance to hit Bastardo’s changeup. In reality, there is no reason for Bastardo to ever throw his changeup especially when you consider that batters see it coming. Over his career, batters swing and miss only 26% of the time. Overall, batters aren’t fooled by the pitch, and they do some real damage when they make contact. Over Bastardo’s last 10 appearances, he is still throwing way too many changeups, and the pitch is still being hit hard and frequently. However, he is able to compensate for that by throwing more sliders.

In what has been Bastardo’s best stretch of the season his slider usage rate is back up to 33%. He is still generating similar swing and miss numbers (39.13%), and batters are still unable to do anything with the pitch hitting .125 off the pitch with an isolated power of .000.

Perhaps more important than the pitch selection is the fact that Bastardo is throwing strikes. The main issue with Bastardo has always been control, and those issues were really prominent to begin the year. In his first 29 appearances, Bastardo was averaging 5.5 walks per nine innings. He was only throwing strikes 60% of the time. Now, he’s getting the ball over the plate throwing strikes 70% of the time. He has only walked one batter over the last 12 innings. With him throwing his slider more frequently, and getting the pitch over the plate, he has become a more effective pitcher. He has become the pitcher the Mets thought they were getting when they signed him to a two year $12 million contract in the offseason. So is he back?

It might be too early to say. We have seen some flashes here and there only to be disappointed once again. The Mets have only used him ONCE over this stretch to get some batters out in a close game. That resulted in Bastardo allowing Daniel Murphy to hit a home run off of him to make it an 8-7 game. Other than that, Bastardo has been used mostly in blowouts and to preserve the bullpen arms when the Mets have been behind. While Bastardo is pitching much more effectively, it is difficult to determine if he’s ready to once again pitch in a pressure filled situation with the game on the line.

With that in mind, the Mets should keep their current 7-8-9 combination as Hansel Robles–Addison Reed–Jeurys Familia. If Bastardo keeps pitching well, he could crack that group for a night or two to give one of those guys a breather. He could also be called on to get big outs in the sixth inning. That could be his role, and he can do it extremely well so long as he keeps throwing his slider, and he keeps throwing strikes.