I think it's SSS and adjusting to the new league. When you are tearing the cover off the ball like he is, you are probably more eager to let it rip. Benintendi struck out a lot when he was initially called up to AA too. After the first 50-100 at bats, his k rates went back to closer to his career rates. The problem with Moncada is even if his k rates normalize, he is always going to strike out a bit. This is why Keith Law probably thinks he will struggle the most in the Majors out of the gate.Can we all agree with that? I'm not so sure.
I don't follow the minors daily but his numbers against LHP in AA are (SSS) abysmal. I posted in the other thread about being worried about his K% in AA being 29%. But it's only 23.5% against RHP which seems like a number that can work for successful ML power hitters.
His K rate against LHP in AA is 52.9%. However, that's really only 17 plate appearances.
His K rate previous to that vs LHP is 22% in 191 PA
versus RHP, the K rate from A to AA is only slightly elevated (22.1% to 23.5%).
Compared to his career OPS splits (vs RHP/ LHP):
2015 Greenville .753/951
2016 Salem .971/.797
2016 Portland 1.118/.508
It's either noise/ small sample size (maybe he's faced a few elite LHPs in AA) or he's going to have a tougher time adjusting against tougher LH pitchers as he moves up.