西武のエース今井達也、圧巻の快投でファン熱狂！次戦の見所は？ (Seibu Ace Tatsuya Imai Dominates—Fans Go Wild! What to Expect in His Next Start)

Japanese ace Tatsuya Imai, 27, formally entered Major League Baseball’s posting system last week, giving all 30 clubs until 5 p.m. ET on January 2 to negotiate a contract with the right-hander after his release by the Saitama Seibu Lions. Why scouts are excited • Dominant 2025 season: Imai logged a 1.92 ERA, 0.95 WHIP and 196 strikeouts over 182 innings in NPB, finishing second in Pacific League Cy Young voting equivalent. • Power arsenal: His four-seam fastball sits 94–96 mph and touches 98, paired with a late-breaking slider and a splitter that produced a 40 percent whiff rate, according to TrackMan data shared with MLB clubs. • Big-game pedigree: The Lions trusted Imai as Opening Day starter three straight years and leaned on him during Japan’s 2023 WBC title run. Posting-fee math and contract projections Under the current MLB–NPB agreement, a signing club must pay Seibu 20 percent of the first $25 million of Imai’s contract, 17.5 percent of the next $25 million, and 15 percent of any amount beyond that. Industry executives expect total outlay—deal plus fee—to land in the $80–90 million range, mirroring Kodai Senga’s five-year, $75 million pact with the Mets in 2022. Teams linked so far • San Francisco Giants: President of baseball operations Farhan Zaidi is prioritizing frontline pitching and has already met with Imai’s representatives in Tokyo, per league sources. • Chicago Cubs: After missing out on Yoshinobu Yamamoto last winter, Chicago reportedly views Imai as a “high-end No. 2 starter” who fits behind ace Justin Steele. • New York Yankees: Brian Cashman dispatched top evaluator Matt Daley to NPB in September; the Yankees like Imai’s fastball-slider combo for Yankee Stadium’s dimensions. Fit with MLB style Analysts note Imai’s splitter induced a .138 opponent average in 2025, a weapon that translates against launch-angle-heavy MLB hitters. The concern: he walked 3.2 batters per nine in Japan. One NL scout said, “If his command tightens, he’s a borderline All-Star; even without it, you’re getting mid-rotation quality on day one.” Timeline and next steps Imai is currently training at Driveline Baseball in Kent, Wash., preparing for December bullpen showcases. Because his negotiating window ends just after New Year’s, contenders are expected to submit final offers before Christmas to avoid losing leverage. If he does not sign by January 2, he must return to Seibu and cannot be posted again until November 2026. Bottom line With a premium heater, swing-and-miss splitter, and a clean bill of health, Tatsuya Imai is poised to become the winter’s most coveted international free agent. Expect a bidding war that could reshape multiple rotations before pitchers and catchers report.