Red Sox pitcher Nathan Eovaldi delivers during the eighth inning...

Red Sox pitcher Nathan Eovaldi delivers during the eighth inning of Game 2 of the World Series against the Dodgers on in Boston.

LOS ANGELES — The Red Sox arrived here two victories from a World Series title, and no one would dispute the idea that Nathan Eovaldi is a significant reason why.

The righthander, who features a fastball that sometimes hits triple digits as well as a nasty cutter mixed in with the occasional sinker, splitter and slider, has been terrific as a starter and reliever this postseason.

And Eovaldi, who has a 1.65 ERA in five postseason outings, including two standout starts, said the seeds for much of that success were sown during his two seasons with the Yankees from 2015-16.

“My split really took off there and it’s still one of my weapons,” Eovaldi said before bringing up, unprompted, Yankees pitching coach Larry Rothschild. “Working with Larry, he helped me, really, with all of my pitches and just how to attack the hitters. He prepared for the games really well and I took a lot away from [working] with him.”

Speaking from his home in Tampa, Rothschild said Eovaldi is among his favorite pitchers with whom he’s worked, regardless of the righty’s difficulties finding consistency as a Yankee.

Eovaldi, Boston’s likely starter for Game 4 here, was 23-11 with the Yankees but had a 4.45 ERA, allowing 298 hits in 279 innings. His 2016 season was cut short when he had to undergo Tommy John surgery — Eovaldi was 9-8 with a 4.76 ERA at the time — and he was designated for assignment that November. Eovaldi didn’t return until May 30 of this season with the Rays, who traded him to the Red Sox at the non-waiver deadline in July.

“He was great to work with, always willing to make adjustments and try different things,” Rothschild said. “He had great arm strength, obviously, but just the type of person he is I think sticks out. Most people that are around him would say the same thing. He’s always positive. I don’t know if he ever has a bad day. A lot of fun to be around and was a really good teammate for everybody.”

Rothschild said Eovaldi’s troubles with the Yankees had little to do with stuff. “Maybe at times he tried to do too many different things,’’ he said, “and now I think he’s settled in and found a couple things that work very well for him and he’s been willing to kind of ride those things, which I think is just a sign of maturing as a pitcher.”

He said Eovaldi’s “tenacity” stood out. “He would have games where things weren’t going very well but he never backed off, he always got after it,” Rothschild said. “When you’re watching him as a coach, at some point you know all that’s going to pay off because there are too many positives in place for him not to be successful at some point.”

Rothschild said Eovaldi was just starting to get a feel for the cutter, a devastating pitch for him this postseason, when he got hurt in 2016. “The cutter is obviously the pitch that has made the difference for him,” Rothschild said. “And I think it’s enhanced his [four-seam] fastball, too, because of the late movement on the cutter and then with the [sometimes 100- mph] fastball, it’s just hard to decipher between the two.”

Rothschild had a better view than he would have liked for Eovaldi’s coming-out party this postseason: Game 3 of the Division Series, when he allowed one run and five hits in seven innings in a 16-1 Boston victory.

Rothschild hasn’t been plugged into the playoffs since the Yankees were eliminated, but he has kept tabs on Eovaldi.

“It’s kind of hard to watch, but obviously I’m pulling for him just because of the personality and the way he was here,” Rothschild said. “I wish him the best, as long as it’s not involving us.”

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