Can these 3 Pirates players sustain success after 2024 breakout seasons?

Dennis Santana

The Pirates picked Dennis Santana off waivers from the New York Yankees. He struggled badly in Pinstripes, putting up an ERA over 6.00. Then, in his second game in Black and Gold, Santana allowed six earned runs in just one inning of work. Fans were reasonably upset that the Pirates picked up this right-handed reliever, who had never shown much in the Major Leagues and hadn’t done much in his first few games to prove otherwise.

But after that one game, Santana went on a tear. His next 42.2 innings saw him put up a 1.27 ERA, 1.97 FIP, and 0.82 WHIP. Santana struck out over 30% of his opponents with a 31.1% K% while inducing a whiff a third of the time. Not only was he striking out a ton of batters, but he was rarely allowing them to get on base via walks. Santana’s walk rate sat at just 5.6%. Hard contact and home runs were not issues, either. When batters made contact vs Santana, they managed a meager 84.3 MPH exit velocity and 2% barrel rate, and the right-hander allowed a single home run. At one point, Santana pitched 24.1 straight frames without allowing an earned run.

Given Santana’s track record before coming to Pittsburgh, fans have reasonably questioned whether he can sustain his strong performance. ERA estimators measured Santana in a good light last year. The right-handed reliever had a 2.59 SIERA and 2.98 xFIP. Santana’s opponent wOBA was .222, but his expected wOBA (xwOBA) was still an elite .243 mark. For reference, there were only 14 qualified pitchers in 2024 with an xwOBA below .250. That indicates he'll remain a sub-3.00 ERA pitcher. Stuff+ only put him at 100 during this hot stretch to end the season, though, meaning that his arsenal displayed as roughly average.

Regardless, his stuff was quite effective. His three most used offerings - his slider, four-seamer, and cutter - each induced an xwOBA below .300, with his two breaking pitches inducing an exit velocity below 85 MPH. Santana’s slider became his most used offering and induced a whiff rate of 41.1%. Only 47 pitchers used a slider against 50+ batters and induced a whiff rate over 40%. 

The pitch that could carry Santana’s success into 2025 is his cutter. He barely used his cutter in prior seasons, but it became his third most-used pitch in ‘24. The right-hander sacrificed some movement on his cutter compared to previous seasons to add nearly two MPH of velocity.
He allowed just seven hits to 42 batters and got a swing and miss 25% of the time with the pitched. Despite the cutter essentially being a brand new pitch to his arsenal, Stuff+ put it as an above average offering at 101. 

Projecting how a reliever will perform is very difficult. Relievers have the most volatility, and even their more advanced metrics have little year-over-year correlation, given the typically small sample size. But Santana did a lot of things right in 2024. Things that good relievers do, including inducing a lot of swings and misses, forcing weak contact, and locating well. Santana doesn’t have to have an ERA in the low 1.00 range. Playing to his ERA estimator numbers will still make him an extremely effective arm out of the Pirates’ bullpen.