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From a very quick examination and viewing of Angels pitcher Jhonathan Diaz, I like what I see. His a 25 year old lefty who pitched towards the end of 2021. He wasn't particularly impressive at the major league level from a peripheral level, striking out too few and walking too many hitters. However, he could have some good potential.
His raw stuff isn't great, but I really like his command. He dots the corners with his changeup very frequently. He throws his changeup so much that he often does make mistakes with it, but the overall package is great. It didn't seem like he liked his fastball very much. As a prospect, he is known for a great sweeping slider and I agree with that assessment. He performed very well in AA/AAA in 2021. FanGraphs only has him as a 35+ FV prospect but I would at least pencil him in for a 40 FV if not 40+. His ceiling might be underrated because he isn't a great power pitcher.