NPB’s Kazuma Okamoto, Tatsuya Imai Expected To Be Posted For MLB Teams

7:34pm: Jon Heyman of The New York Post writes that Okamoto and Imai are indeed both expected to be posted this offseason.

12:24pm: Every offseason, a handful of high-profile players from Japan’s Nippon Professional Baseball and the Korea Baseball Organization in South Korea either reach true free agency or are made available to MLB teams by way of the posting system. We already know that slugging third baseman Munetaka Murakami (NPB’s Yakult Swallows) and steady right-hander Kona Takahashi (NPB’s Seibu Lions) will be posted this winter. Breakout infielder Sung Mun Song (KBO’s Kiwoom Heroes) is hoping to be posted for big league clubs as well. ESPN’s Jeff Passan reports this morning that Yomiuri Giants third baseman Kazuma Okamoto and Seibu Lions righty Tatsuya Imai are also hoping to be posted by their clubs and make the jump to Major League Baseball.

The hope of being posted is notable, but that also does not guarantee either player will be available to North American clubs this winter. Yakyu Cosmopolitan — a terrific source for English-speaking fans with an interest in Japanese baseball — points out that NPB’s Giants are a typically anti-posting club who rarely make their stars available to MLB teams. Okamoto is the Giants’ captain. The Lions are more amenable to posting players, but they’ve already agreed to post Takahashi. Posting two members of their rotation would be difficult, but YC notes that Imai would be a true free agent after the 2026 season. The Lions could lose him for nothing in the 2026-27 offseason anyhow.

Okamoto turned 29 in June. He’s a six-time All-Star and two-time Gold Glove winner who’s thrice led NPB in home runs. He missed more than three months of the current season after injuring his elbow in a collision at first base, but he’s healthy again and is batting .304/.385/.585 with 11 homers, 13 doubles, a triple and nearly as many walks (10.2%) as strikeouts (11.2%) in 196 plate appearances. Okamoto averaged 34 homers per season from 2018-23, “slipped” to 27 last year, and is now homering at the third-best rate of his career (once every 17.8 plate appearances).

Okamoto has been on the radar of MLB scouts for several years now, but if the Giants are going to post him, this will be the time to do it. Like Imai, he’ll have the requisite nine years of service to become a true free agent after the 2026 season. That hasn’t stopped the Yomiuri club from holding onto stars in the past. However, if Okamoto is set on eventually making a move to North America, the Giants’ decision boils down to posting him now and reaping a notable sum via the posting system or allowing him to walk with no compensation next winter.

The right-handed-hitting Okamoto played primarily third base early in his NPB career, but he’s seen significant time at first and has a handful of starts in the outfield corners as well. Okamoto has split his time between the corners this year but was primarily a first baseman in 2024. Sports Info Solutions credited him with the Fielding Bible Award as NPB’s best defender at first base in 2024, and Passan suggests that some MLB teams feel he’s better suited at first than at third.

Eric Longenhagen of FanGraphs agrees, labeling Okamoto as a “likely first-base-only defender” in the majors but crediting his plus power and consistent ability to pull the ball with authority. Longenhagen notes that, as is the case with most NPB hitters, there are questions about Okamoto’s ability to hit big league fastballs. The average NPB fastball is around 91 mph, compared to this year’s 94.4 mph average four-seamer in MLB (via Statcast). Longenhagen writes that Okamoto’s numbers against heaters greater than 94 mph “fall off a cliff.” It’s a valid concern, though the counter is always that a hitter could potentially adapt to better velocity when seeing it more frequently. That uncertainty will be baked into eventual price of a free agent contract if Okamoto is posted.

Even if Okamoto is limited to primarily playing first base, he’s a good defender there by all accounts. He has plus power, improving contact skills and draws plenty of walks. Since settling in as a regular in his age-22 season, Okamoto is a .276/.360/.524 hitter with an average of 39 homers per 162 games played. He currently has a career-low strikeout rate and the second-best ISO (slugging minus batting average) of his career. If he’s posted, there will surely be multi-year interest from MLB clubs.

Imai’s possible addition to the market is arguably even more intriguing, given the heavy price teams are willing to pay for prime-aged pitching. The 5’11” righty won’t turn 28 until next May. He’s in the midst of a career-best season, sporting a comical 1.50 ERA with a 28.8% strikeout rate and 6.7% walk rate in 143 2/3 innings. Dating back to the 2022 season, Imai boasts a sensational 2.10 earned run average. Passan notes that the right-hander sits 95 mph with his heater and tops out at 99 mph, giving him the sort of power arsenal that’s quite rare in NPB.

An ankle injury held him to nine games back in 2022, but Imai has topped 130 innings in three seasons since and is averaging seven innings per start for a second consecutive season. He’s on pace for back-to-back seasons of more than 170 innings. (Bear in mind that the NPB season is 144 games, not 162 as in MLB, and Japanese pitchers typically only start once per week.) Imai currently ranks seventh in NPB in innings pitched, and the six names ahead of him all have at least one extra start over him. He’s averaged more innings per start than all but one of those pitchers ahead of him on that leaderboard.

Passan writes that he polled more than a dozen scouts and front office executives on the type of contract Imai could command, with estimates ranging from $80MM on the low end to nearly $200MM on the high end. He’ll be three years older than Yoshinobu Yamamoto was when he landed his precedent-setting $325MM contract with the Dodgers but two years younger than Shota Imanaga was when he signed a four-year, $53MM deal that now looks like a bargain for the Cubs (and still will even after Chicago picks up an option to push the deal to $80MM over five years).

If Imai is posted, he’ll join Dustin May and Michael Soroka as free agent starters heading into their age-28 seasons. Imai would have considerably more earning power than either, as big league teams will pay a premium for his power arsenal and the allure of the unknown. Based on Imai’s age, arsenal and recent track record, there’s a chance that he could be the highest-paid pitcher of the entire free agent class this winter — if the Lions eventually choose to make him available.

For those in need of a refresher, the MLB-NPB posting system allows Japanese teams to post their players for all 30 MLB teams at their discretion. Players that are 25 or older and have six-plus years of experience can sign major league contracts for any length and any amount. When a player is posted, that opens a 45-day window for him to negotiate with any and all interested MLB clubs.

When a deal is reached, the MLB team must pay a posting/release fee to the player’s former NPB club. That sum is equal to 20% of the contract’s first $25MM, 17.5% of the next $25MM and 15% of any money thereafter. That sum comes in addition to the contract. Any down-the-road earnings (e.g. club options, performance bonuses, etc.) are also factored in once they become guaranteed. For instance, if Imai were to sign a $125MM contract with an eventual club option for $25MM, his MLB team would owe the Lions an additional $3.75MM (15%) upon exercising that club option.