At the 2024 trade deadline, the Philadelphia Phillies sent a pair of highly-regarded pitching prospects to the Los Angeles Angels in exchange for a half-season rental of Carlos Estévez. Estévez was a solid contributor down the stretch, but giving up two promising young arms in George Klassen and Sam Aldegheri for just 21 innings of Estévez could eventually result in some regret.
Aldegheri made his big league debut with the Angels last season in a truly bizarre fashion, with the team having him serve as an occasional mop-up man in short stints rather than let him continue to develop as a starter. It did not go well.
Now, Klassen, who at the time of the trade was the higher-ranked hurler, coming in at No. 5 on Philadelphia's top-30 prospects list, is up and trying to rebound from a very rough debut. The 24-year-old lasted just 2 2/3 innings, giving up 2 earned runs, three hits, and five walks in a very inefficient outing.
Final line for #Angels No. 4 prospect George Klassen: 2 2/3 IP, 3 H, 2 ER, 5 BB, 4 K. He threw 73 pitches (40 strikes). Fastball averaged 97.1 mph. He got 12 swings and misses, including six with his slider and four with his four-seamer.
— Rhett Bollinger (@RhettBollinger) April 5, 2026
He'll take the hill for Los Angeles again on Saturday for his second major league start, looking to rebound and establish himself, potentially carving out a lasting role as injuries have left the rotation short.
Former Phillies top prospect George Klassen faces uphill battle as he tries to break into MLB with Angels
When the Phillies selected Klassen in the sixth round of the 2023 draft, he was a tantalizing arm but a real project. He came out of the University of Minnesota having hardly pitched. After undergoing Tommy John surgery in 2021, he managed just 64 1/3 total collegiate innings and struggled mightily to harness his stuff, walking nearly as many batters (47) as he struck out (49) during his 2023 season.
The positive was that he sits in the high-90s, can touch 100 with his fastball and has a wicked slider, which gave him a tremendous foundation if he could figure out his command. At the time of the trade, the Phillies had him at Hi-A Jersey Shore, but the Angels are super aggressive with all of their prospects and quickly sent him to Double-A.
He got off to a hot start in Double-A last season, but struggled as the year went on at the level, posting a 5.35 ERA before moving on to make his final start of the year at Triple-A. He made one start at Triple-A this season, meaning he's thrown just 10 2/3 innings at the minors' highest level in total.
Keep in mind, this is a hurler who needed a lot of development, so the aggressiveness is really questionable. The Angels don't have a great track record at developing prospects overall, but they're particularly bad when it comes to fostering growth among young pitchers.
Aldegheri's standing took a real tumble after the shenanigans they pulled with him last year, falling from No. 5 in their system down to No. 16 heading into 2026. In a fit of madness that's even more illuminating of their failures, they insanely drafted 20 pitchers, their entire allotment of picks, in 2021, and have not found a single regular contributor from what their fans not-so-affectionately refer to as "The All-Pitcher Draft."
Klassen is extremely talented, and in another organization might develop into a stud who makes Philadelphia regret shipping him out, but with the Angels, it will be really tough for him to reach his ceiling. Maybe he comes through and gets into a rhythm beginning with his second start, but the odds are against him through no fault of his own.