A decision by a high school baseball coach to rest his star pitcher in a crucial qualifying game for the prestigious national tournament has the Japanese sports fraternity up in arms.

The gamble ended in defeat, and the Ofunato High School was inundated with phone calls from people demanding an explanation.

It sparked harsh criticism of the coach but also a wider debate about the popular tournament's win-at-all-costs approach, with even Chicago Cubs pitcher Yu Darvish weighing in.

The debate has entered a second week. Ofunato manager Yohei Kokubo opted not to use ace pitcher Roki Sasaki in the final of the Iwate Prefecture qualifier on July 25. His team needed to win the game to seal a spot in the National High School Baseball Championship — commonly known as Koshien — which in Japan carries the same weight as March Madness, the NCAA Division 1 men's basketball tournament in the United States.

But with Sasaki on the bench, Ofunato lost 12-2 to Hanamaki Higashi High School.

Sasaki, an 18-year-old right-hander, had already thrown 435 pitches from July 16 to 24 and would have had to pitch the game against Hanamaki after throwing 129 pitches in the semifinals and 194 pitches over 12 innings three days before that.

Sasaki reportedly had some elbow discomfort, though the school has denied this. Kokudo said the reason for keeping Sasaki out was to prevent injury.

"I think Sasaki's manager showed a lot of courage," said Robert Whiting, who has written books on Japanese baseball. "He could have won the national title with Sasaki if he had followed the usual pattern of throwing the team ace out there on consecutive days."

Asked about the decision, Sasaki stoically said he wanted to pitch but the manager's decision was final.

An unapologetic Kokubo said he'd had the pitcher's well-being in mind.

"The reason was to prevent injury," Kokubo said.

Asked after the game whether winning was less important than Sasaki's future, Kokubo was defiant.

"That's certainly not the case," he said. "Our goal is to win, regardless of whether Sasaki pitches or not."

Japanese baseball great Isao Harimoto, known for his old-school views, described Kokubo's decision as hugely disappointing, saying young players need to face adversity to meet the harsh challenges of baseball.

Darvish, a former Japanese high school standout himself, disagreed.

"Those who say things like asking why (Sasaki) didn't pitch are not giving a single thought to the kids," Darvish told Japan's national news agency, Kyodo.

Kokubo's decision has been widely discussed on weekly news programs with numerous former professionals, current players and TV personalities all chiming in with analysis and opinions.

Sasaki has a fastball that has been clocked at 163 kph (101 mph) and hit 160 (99.4) during his 194-pitch outing. He's already drawing comparisons with players like Shohei Ohtani and Daisuke Matsuzaka, the former major leaguer who threw 250 pitches in 17 innings in the quarterfinals of the 1998 Summer high school baseball tournament, one day after a 148-pitch complete game shutout.

For those not familiar with the game, most teams in Major League Baseball stick to a general guideline of 100 pitches for starting pitchers in order to avoid the kind of strain that could lead to injury.

Matsuzaka, who underwent Tommy John surgery in 2011 while with the Boston Red Sox, is currently pitching for the Chunichi Dragons but has missed most of this season with an arm injury.

Sasaki has already been widely scouted by teams in MLB.

Marathon pitching outings on consecutive days have long been commonplace in Japanese high school baseball tournaments. Pitching a complete game, even those going into extra innings, is seen as an expression of the fighting spirit that dominates Japan's sports culture.

But times are changing, even in the tradition-bound world of Japanese high school baseball where players shave their heads, go through grueling practice sessions and adhere to strict codes of conduct.

Amateur baseball officials are considering the introduction of pitch limits aimed at preventing injuries to high school players.

The Japan high school federation has taken several other steps to protect players during the summer tournament which is played in sweltering heat. In 2000, it capped the number of extra innings to 15, down from 18. In 2013, it introduced a rest day after the quarterfinals.

Whether Kokubo's decision will lead to change is yet to be known.

"It's too early to tell whether this is a groundbreaking decision," Whiting said. "Wait until the last few days of the Koshien tournament to see how many aces are rested. My guess is that the two pitchers in the final will have pitched three complete games in a row."