Prized Japanese pitcher Roki Sasaki says in an Instagram post he intends to sign with the World Series champion Los Angeles Dodgers.

A 23-year-old right-hander whose fastball tops 100 mph, Sasaki will join fellow Japanese stars Shohei Ohtani and Yoshinobu Yamamoto in a move many baseball executives have long expected.

The San Diego Padres and Toronto Blue Jays were said to be the other finalists still in pursuit of Sasaki, who has until next Thursday to finalize a contract.

"I have signed a minor contract with the Los Angeles Dodgers," Sasaki's post said, in Japanese. "It was a very difficult decision, but I will do my best I can feel this was a correct decision, once I look back on my life as a baseball player. At my news conference for joining the club, I hope to wear my Dodgers uniform, feeling gratitude for all those who have supported me."

Los Angeles has up to $5,146,200 US available in its international signing bonus pool, though the Dodgers could make trades in the next week to increase the amount by up to 60 per cent.

The Dodgers are planning to use a six-man rotation, which could ease Sasaki's transition to Major League Baseball, as the Dodgers attempt to become the first repeat champion since the New York Yankees from 1998 to 2000.

The Marines will get a release fee calculated at 25 per cent of the amount of Sasaki's signing bonus.

During a news conference at the winter meetings last month, Sasaki's agent, Joel Wolfe, denied an agreement with the Dodgers was already in place. Wolfe said MLB had investigated.

"There was a lot of discussion in the media, in the league, in NPB about Roki's situation," Wolfe said. "There were some accusations, allegations, all of them false, made about predetermined deals, things like that. However, MLB rightly wanted to make sure that this was going to be a fair and level playing field for everyone, so they did their due diligence and interviewed numerous parties ahead of time to make sure that that was the case."

Sasaki was 10-5 with a 2.35 ERA in 18 games last year, striking out 129 hitters in 111 innings during a season limited by shoulder inflammation. He went 7-4 with a 1.78 ERA in 15 starts in 2023, when he had an oblique injury. He has a 29-15 career record with a 2.10 ERA over four seasons with the Marines and pitched a perfect game against Orix in April 2022.

The Dodgers' first spring training workout is on Feb. 11 at Glendale, Arizona, ahead of their opening two-game series against the Chicago Cubs in Tokyo on March 18 and 19.