2B is up the middle and just as criticsl as CF defensively.
I disagree. You can plug a substandard defensive player in at 2B. Teams have done this for years sacrificing defense for offense. For instance, Daniel Murphy, Rougned Odor, and Chase Utley all played over 1000 innings at 2B with negative defensive metrics. I'd make the case that CF is even more important defensively than SS. A CF who can't get to the gaps gives up doubles while a SS/2B who doesn't have range generally speaking is giving up singles. And even if your assertion of 2B being just as important defensively is accurate, there flat out aren't enough CF in the league worth talking about. There were 12 CF who had 2 or higher fWAR and about half of those did it on defense mostly a la Kevin Pillar. There were 17 2B. In other words, if Happ could play CF he's far more valuable there.
The vast majority of CF prospects look something like DJ Wilson does which is to say a 60/50/60 or higher grades on run/throw/field. Happ had 55/55/45. If you have good instincts you can get by with that run grade. For instance, Almora had a 50 run grade but he's got one of the best first steps in baseball. Like wise, you will often see teams skimp a bit on CF arms because the lack of depth at the position. But generally speaking, teams don't skimp on fielding. So, long story short, Happ can probably play CF in a pinch but you don't want him starting 150 games there.
And none of that is to crap on Happ because I think he's a fine 2B prospect. All I'm saying is there's no way he's realistically playing CF full time.
