TOKYO (Kyodo) -- The Lotte Marines of Nippon Professional Baseball said Tuesday they have completed the procedures to make star pitcher Roki Sasaki available to major league teams via the posting system.

A 45-day negotiating window opens for the talented but injury-prone 23-year-old, one of the most sought-after pitchers this offseason, once he is posted.

Since Sasaki is under 25, he will be classified as an international amateur free agent subject to bonus pool limits, according to Major League Baseball rules.

That means the hard-throwing right-hander's first contract will be a minor league deal.

The 2024 international signing period ends Dec. 15, and the 2025 period begins Jan. 15. Sasaki is expected to sign a contract in late January, according to U.S. media.

Sasaki posted a career-high 10 wins against five losses with a 2.35 ERA in 18 games this year, striking out 129 batters in 111 innings.

The Iwate Prefecture native has a 29-15 career record with a 2.10 ERA over four seasons with the Marines. His fastball has been clocked as fast as 165 kilometers (102.5 miles) per hour.

On April 10, 2022, Sasaki became the youngest pitcher in NPB history to throw a perfect game at 20 years, five months. In his next start a week later, he threw eight perfect innings before being replaced by a reliever at the start of the ninth.