Yankees watching Orix Buffaloes righthander Yoshinobu Yamamoto

ST. PETERSBURG, Fla. — Not surprisingly, the Yankees are one of many big-league clubs with significant interest in one of the top arms in Japan.

It is the one belonging to Orix Buffaloes righthander Yoshinobu Yamamoto, a star in this year’s World Baseball Classic who is expected to be posted this offseason. Matt Daley, the Yankees' director of pro scouting, is in Japan watching Yamamoto (as well as other top players in Nippon Professional Baseball, Japan’s highest level of baseball, who could be posted either this year or in years to come). 

Yamamoto, 25, who features a high-90s four-seam fastball as well as a splitter, cutter and curveball, is 12-5 with a 1.42 ERA in 18 games, striking out 128 and walking 20 in 127 innings.

This is not the Yankees’ first look at Yamamoto. They had another of their top pro scouts in Japan watching  him — and others — earlier in the season.

Bader still scuffling

Harrison Bader went 0-for-3 with a strikeout Saturday, dropping him into a 7-for-49 (.143) skid with 15 strikeouts in his last 15 games.

“It’s been rough,” said Bader, who is hitting .246 with a .661 OPS. “I think every day you just have to continue to trust your process. When the game starts, you just remain confident and go up there and put together winning at-bats with a winning mentality, which is what I’m trying to do. I’m trying to keep everything really simple. Obviously, from a results standpoint, it’s not what I want, not what I want to be for this team to help us put runs on the board. But again, the work never stops.”

Catching up

Ben Rortvedt caught Clarke Schmidt on Saturday, making it two straight starts behind the plate for the backup catcher. Aaron  Boone said not to make too much of it and that Kyle Higashioka essentially remains the primary catcher.

“Higgy will catch [Sunday] and will probably catch at least two, maybe three [of the games in Detroit from Monday through Thursday],”  Boone said before Saturday’s 3-0 loss. “It’s more just coincidental.”

Rortvedt and Cole quite a duo

Rortvedt, who is hitting .122, became Gerrit Cole’s de facto personal catcher after Jose Trevino suffered a season-ending wrist injury. Cole allowed two runs (one earned) and three hits in 7 2/3 innings Friday night, striking out 11 to match a season high.

The ace’s on-field dynamic with Rortvedt, which includes some spirited in-game discussions regarding pitch selection, has garnered some attention. It is a source of amusement in the clubhouse.

“That’s Gerrit when he’s pitching,” Boone said with a smile. “He expects a lot, demands a lot and he’s going to wear it on his sleeve. So you have to be able to match him and even challenge him. And so far I feel like Ben’s really held his own in that regard.”

Day off for Volpe

Anthony Volpe, who entered Saturday having appeared in each of the Yankees' 128 games, was given a  day off and was replaced at short by Oswald Peraza.

The most games for the 22-year-old  in a season were the 132 he appeared in last season in combined stints with Double-A Somerset and Triple-A Scranton/Wilkes-Barre.

“I think there’s value in the fact that he’s played [mostly] every day,” Boone said. “Certainly want to be mindful he’s never gone through and played a full major league season through the month of September . . . whether it’s 152, 162, 156, you like to see those kind of numbers. His ability to post, I think his ability to stay physically sound [has] been encouraging. Going through the grind of your first season at this level [as the] Yankees' shortstop, I think he’s handled it really well.”

Donaldson, Rizzo face live pitching

Josh Donaldson, on the 60-day injured list with a right calf strain, and Anthony Rizzo, out since Aug. 3 with post-concussion syndrome, faced rehabbing pitcher Luis Gil on Saturday morning at the team’s minor-league complex in Tampa in simulated game action. Boone said both are close to beginning rehab assignments, though not to the point that any dates have been set.