By now, everyone should have learned..or should now learn that minor league players don't always get promoted and storm the field. Most fantasy news writers have to write something to get paid - hence they'll write and hype up someone as a callup that'll change the league and is undeniably a keeper. I learned that lesson a few years back when BJ Upton was called up the first time...mostly because about a week before Upton was called up...some guy named David Wright was called up, I passed on Wright because I wanted Upton, the guy that was going to be the core of my keeper team....yeah. That worked out just fine

......
Lesson to learn, it's not bad to grab these guys...but never EVER depend on them to get you anything beyond sit on your bench.
Anyway. Eventually I think Upton will be solid...I'm not sold on him being an all-star or the key piece to the Devil Rays eventual 2025 Championship...but hey, give him time if you can afford to in a keeper league.
(PS - I do understand the disappointment with Upton right now, since I'm in first and was looking to gain some cushion points with his SB propelling me upwards...so much for that theory)