When Masahiro Tanaka arrived in Japan, he admitted he would have to get used to EVERYTHING, since many regulars now were not playing back in his last season with the Rakuten Eagles in 2013.

This was never more apparent than on Saturday, when — as he had in his first start — he came up against guys looking for fastballs — and threw hard, straight ones up in the zone.

Tanaka’s velocity isn’t what it was before he suffered his elbow sprain in 2014. He really knows how to pitch, and in addition to his four-seamer, splitter and his two sliders, he can throw a two-seamer, a cutter, a curve and a change.

Tanaka threw a good game, but was punished for his mistakes: the four-seamer and two-seamer that went over the fence and a high slider in the first inning that led to a run.

But I have to think that the quality of hitting in Japan is taking Tanaka by surprise. Granted, his good fastballs back in 1993 were closer to 98 mph than 94 — where they are now — but I doubt fewer non-sluggers were able to drive his mistakes over the fence as easily as they have since he came back.

Tanaka’s location is still not as precise as we’ve grown accustomed to, and he’s going to have to do something to execute his fastball better. He’s been falling back on the two-seamer, because it’s unexpected. But as the season goes on, I’m going to be watching the quality of his four-seamers, because that was the pitch that really allowed him to weaponize his slider with the Yankees.