Phillies improve bullpen with Carlos Estévez acquisition, Angels get strong return

Deal details: Philadelphia Phillies acquire RHP Carlos Estévez from the Los Angeles Angels in exchange for RHP George Klassen and LHP Samuel Aldegheri

The Angels are finally selling, and their first move seems to be a strong one, as they dealt a reliever they don’t need and who’s heading for free agency for two solid pitching prospects. Meanwhile, the Phillies get another quality arm for their bullpen, and they capitalize on player development’s great work with one of the two prospects they traded, although I think this is a steep price for a rental reliever.

Right-hander Carlos Estévez is in the midst of a well-timed career year, posting what is by far his lowest-ever unintentional walk rate, just 2.4 percent, about a third of his previous best rate set back in 2019 (7.2 percent). He works in the upper 90s with a short slider that hitters don’t pick up very well, throwing an occasional changeup, although he doesn’t miss as many bats as you might expect from the stuff and he gives up a lot of line drives and more hard contact than you’d want for a high-leverage reliever.

The Phillies just traded right-hander Seranthony Domínguez the other day, and Estévez should just take Domínguez’s spot in the bullpen hierarchy, offering better control and probably less volatility, but slotting in below the Phillies’ best relievers when it comes to working in the highest leverage situations.

George Klassen has taken a huge step forward since joining the Phillies’ organization. (Nathan Ray / Clearwater Threshers)

This return for a two-month rental of a good reliever seems fantastic. Right-hander George Klassen has been one of the best development stories in the minors this year, as the 2023 sixth-round pick has established himself as a viable relief prospect in his own right.

He had a miserable spring in 2023 at the University of Minnesota where he walked 47 batters in 56 2/3 innings and posted a 5.72 ERA, pushing him down three-to-four rounds from where he was loosely expected to go coming into that season. His inability to locate his upper-90s fastball was a huge part of the problem.

He’s been far more effective this year, dominating Low-A hitters before a promotion in June to High A, where he’s been successful but where his 45 (on the 20-80 scouting scale) control and lack of a pitch to use against lefties has given him some trouble. The Phillies haven’t done much with his delivery, which is still pretty high-effort, but they have him mixing his pitches a lot more, and his slider is now closer to a hybrid slider/cutter that seems to be helping to keep hitters off the four-seamer, which is high-spin but doesn’t have much movement.

Klassen still profiles as a future reliever, as it’s 40 command even after the improvements and I don’t think the cutter is going to be the weapon he’d need to face left-handed batters two to three times in a game, but he’ll hit 100 mph in relief and the two breaking pitches should be more than enough when he’s not turning a lineup over.

Left-hander Samuel Aldegheri is the opposite sort of prospect from Klassen, as he’s all finesse and deception but his fastball, while improved, is still below-average. The gentleman from Verona, Italy, works with a four-pitch mix led by two breaking balls that are slightly above average, with a fastball that sits 90-92 and a grade 45 changeup.

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The pitching paisan: Sam Aldegheri, a Phillies prospect from Italy, dreams of MLB

He’s destroyed lefties this year between High A and Double A, holding them to a .140/.221/.151 line with just one extra-base hit allowed in 134 PA, but right-handers have hit him harder and he’ll need to find a better option against right-handed hitters to remain a starter, either by altering the changeup or trying a splitter.

Aldegheri has a short stride and everything he throws moves vertically, with nothing to really help him work more side-to-side in or beyond the zone. He’s improved quite a bit since entering the Phillies’ system as a 19-year-old in 2021, and I do think there are a few ways he could continue to progress to end up a fourth starter rather than the future fifth starter/swingman he projects to be right now.

(Top photo of Estévez: Troy Taormina / USA Today)