The first and most important thing you must realize about Konnor Griffin — baseball's top prospect, freshly called up ahead of Pittsburgh's home opener — is that you should probably trade him away today in your non-dynasty leagues.
In all likelihood, Griffin's 2026 fantasy value is peaking right now, ahead of his debut. The savvy move is to flip him as soon as possible, while everyone is buzzing about his arrival. Griffin is a teenager as of this writing; he won't turn 20 for another three weeks. At his age, if he can simply tread water in the majors and not look like a fool at every moment, he will put himself in rare company historically. At 19 or 20, it's perfectly fine if he fails. Anyone would fail.
In fact, the full list of every position player in history who achieved a 3.0 WAR season at age 19 is just four guys — four, in 150-plus years of professional baseball. Griffin is probably going to be a pretty ordinary hitter this season, and it's fine.
Again, as a teenage rookie, if he can simply scuffle in the usual manner of league-average players with flashy traits, it's a positive sign. A great sign. Hitting a baseball is nearly impossible.
But obviously I'm being a buzzkill on Griffin, a thrilling player with power, speed and on-base ability who hit four bombs this spring and crushed Triple-A pitching for a week (7-for-16, 5 BB). It's tremendous that baseball has finally reached the point at which teams like the Pirates are willing to promote prospects like Griffin at the exact moment they might be ready. His arrival is a delight.
As a practical matter, you should definitely trade him in fantasy because the excitement attached to situations like this invariably exceeds the payoff. And yet you'd also have to be an unfeeling sociopath to trade Konnor [expletive] Griffin, because he's a party. He's fun. He hit 21 home runs and stole 65 bases in the minors last season as an actual child.
Alas, I will not be trading Griffin in either of the leagues in which I've rostered him, because I'm not a monster. Let's root for fun things. Let's hope Pittsburgh gets something right.