It wasn’t fun when New York Mets reliever Seth Lugo had to halt his preparations for 2021 during spring training and go under the knife for elbow surgery. This was mostly the case because Lugo has been a crucial piece to New York’s bullpen in recent years, and on many occasions, the only reliable relief pitcher to be called upon in Flushing.

But in going along with the mantra for this club throughout the season, the rest of the relief corps was up to the task before Lugo finally made his season debut on June 2. While Lugo was on the sideline, manager Luis Rojas saw his bullpen post 2.9 fWAR in 165 1/3 innings, which was tied with the Chicago Cubs and Chicago White Sox for the best in baseball at the time. New York’s 3.59 bullpen ERA was also within the top-10 of the league.

When Lugo did get activated, it felt like this part of the roster was about to get a tremendous boost if he could quickly return to form. That’s exactly what the 31-year-old right-hander has done thus far. Although he’s only tossed 15 innings, he’s looked dominant with a 35.0% strikeout rate, a 10.0% walk rate, a 2.40 ERA, and a 2.80 SIERA. His 0.60 home runs allowed per nine innings is more in line with his career norms after post a 1.96 mark in 2020, and his 0.4 fWAR is the same as what he did in 2020 through 36 2/3 innings.

We’re obviously going to be talking about some very small sample sizes, not only because Lugo is a reliever, but also because his season didn’t get underway until the beginning of June. With that in mind, though, it’s worth noting how the two pitches that have typically been the most effective throughout his career have seemingly taken another step forward in the early going.

Back to Old Tricks

During the 2018 season, when Lugo was almost exclusively used out of the bullpen for the first time (he made five starts out of 54 total appearances), he hit a couple of noticeable benchmarks with his fastball and curveball. Mainly, it was decreasing the usage of one in order to amp up the other.

He tossed his fastball a career-low 48.6% of the time while using his curveball at a career-high 31.9% clip. Although he was even better in 2019, this began a two-year trend where his usage went in the opposite direction. His fastball usage settled in at 56.9% and 55.4%, respectively, and the use of his curveball continually dropped, going from that 31.9% clip to 23.7% and then to 19.3%.

Again, we’re talking about small sample sizes here, but his usage of each offering is more in line with what he did in 2018. Lugo is tossing his fastball at a 51.9% rate so far in 2021, and he’s using his curveball 28.3% of the time. Both of these marks are on pace to be his second-lowest and second-highest usage rates, respectively.

Effectiveness Is Through The Roof

What’s really eye-popping is the type of results he’s gotten from these two pitches to this point, and that’s especially the case when we drill down his fastball usage to just his four-seamer. He’s thrown that offering and his curveball 66 times each, and it’s hard not to have your jaw drop at the production, especially when compared to 2020.

Here’s how his four-seamer performance has looked to this point:

And, here’s how his curveball has performed:

The effectiveness of his curveball has obviously increased from last year — as has his control — but that’s not necessarily anything that’s new. Lugo’s bender has historically been his most effective pitch when wRC+ is used as the benchmark. What really jumps off the page is how drastic of a turnaround his four-seamer has taken through his first 15 innings this season.

It’s interesting because his four-seamer has been tossed in the strike zone much more often this year (57.6%) than last year (48.8%). Despite this, he’s generated swings outside the strike zone way more often (24.8% in ’20, 42.9% in ’21) than he has inside the strike zone (62.0% in ’20, 60.5% in ’21). He’s also seen a significant rise in swinging-strike rate compared to last year (12.7% to 21.2%). In fact, Lugo has never generated a rate higher than 13.0% in this category for an entire season, so this would definitely be unchartered territory if he’s able to sustain it moving forward.

The Beauty of an Effective Bullpen

Between 2017 and 2019, Lugo was easily New York’s most important reliever. With overall bullpen performance being lackluster throughout that time, it also made him the most used reliever by a comfortable margin. He led Mets relief pitchers with 161 1/3 innings pitched during that three-season span, with Robert Gsellman‘s 147 2/3 frames coming in a somewhat distant second place.

Despite registering the most innings, Lugo also appeared in the fewest games among the four Mets relievers who had thrown 100-plus innings during this period (Gsellman, Paul Sewald, and Jeurys Familia). So, it wasn’t just being used a lot, but getting used a lot and being asked to get more than three outs rather frequently.

In his 15 appearances so far in 2021, he’s pitched more than one inning just twice. Part of it is him still being fresh off surgery, but another part is Rojas having more than one dependable arm to call upon throughout the course of a game. In addition to not being used in multiple innings very often yet, he’s already appeared for fewer than three outs on four occasions out. In 61 appearances in 2019, he tossed less than one inning just six times.

So, he’s potentially getting a little more rest and not being used as liberally as he has been in the past, and it seems like his two most effective pitches are reaping the benefits of it all. Lugo will remain a crucial part of the Mets’ bullpen as summer turns to fall, and having him with a fresher arm down the stretch than he has in recent years is never a bad idea.