With Japan already gearing up for the next World Baseball Classic in 2017, Sadaharu Oh said Tuesday that Boston Red Sox reliever Junichi Tazawa has virtually no chance of playing for his country when the next tournament rolls around.

Oh, who was the manager for Japan when it won the first WBC title in 2006, told Kyodo News that Japan’s national team is an exclusive club, the preserve of players who worked their way up through the ranks in Japanese pro ball. Tazawa, a blue-chip prospect as a corporate leaguer, turned his back on Nippon Professional Baseball and signed with the Red Sox as an amateur in 2008.

“He never played (professionally) in Japan,” Oh said. “If he had been part of the team, it would have been difficult for him.

“I can’t really say about 2017, but it is only natural that we will select the best representatives of Japanese pro baseball. There’s nothing we can do about that. Even in America, players who are not currently playing in the U.S. are excluded.

“We only consider those players who’ve been a part of Japanese baseball as Japanese players. Tazawa is a special case. This is the road that Tazawa chose. He wasn’t passed over by Japanese pro baseball. It’s kind of too bad for Tazawa. But this is a rule we have within the baseball community.”

Tazawa, a 28-year-old right-hander who has established himself as the Red Sox setup man for closer and countryman Koji Uehara, has a career ERA of 3.37 over 192-1/3 innings with 189 strikeouts. Without him — and when Japan’s major leaguers who were invited all declined — Japan failed to win the WBC for the first time, crashing out in the semifinal stage in San Francisco under manager Koji Yamamoto.

Oh said his role as a special advisor to the national team has diminished with time, due to the fact that Yomiuri Giants skipper Tatsunori Hara had won in 2009 and that a lot of today’s players were less familiar to him.

He said he had no part in Tazawa’s omission from the 2013 team, when every other Japanese with a major league contract was asked to play. According to head coach Masataka Nashida and pitching coach Tsuyoshi Yoda, Tazawa’s name never came up during staff meetings to decide the squad.

“I don’t think it was Mr. Yamamoto (who decided to leave him out),” Oh said. “He was never really a candidate.”

“I don’t think he’ll be considered for 2017, either. That’s just the way it is.”