The Saitama Seibu Lions announced (Japanese language link) on their official team website that they have accepted Tatsuya Imai’s request to be posted to Major League teams. Once Imai is officially posted, he’ll have 45 days to work out a contract with a big league team, or else he’ll return to the Lions for the 2026 Nippon Professional Baseball season.
It has been over two months since reports first surfaced about the likelihood of Imai’s availability this winter, and today’s news officially confirms the three-time NPB All-Star as one of the most intriguing arms of the 2025-26 free agent class. Imai has a 3.15 ERA over 963 2/3 career innings with the Lions, with a 22.31% strikeout rate and a 11.52% walk rate. While that career walk rate is on the high side, Imai has reduced that number in each of his last four seasons, and he had a very solid 7.02% walk rate over 163 2/3 innings in 2025.
Imai is only 27, and doesn’t turn 28 until May. Between his age and an intriguing four-pitch arsenal (headlined by a fastball in the 95-99mph range and a plus slider), there’s a lot to like in terms of how Imai’s success in NPB might translate against Major League hitters. This upside led MLBTR to place Imai seventh on our list of the offseason’s top 50 free agents, and we’re predicting a six-year, $150MM deal even though some evaluators feel Imai projects as a back-end starter or even as a reliever in the majors.
Imai qualifies for full free agency next offseason, so the Lions may feel that they can at least earn some money back via a posting free by letting Imai go now rather than 12 months from now. As per the terms of the MLB-NPB posting system, any Major League team that reaches an agreement with Imai will owe the Lions a staggered fee depending on the size of the deal, and on any future earnings (i.e. options, bonuses, etc.) attached to that initial contract.
The Lions will get 20% of the contract’s first $25MM, 17.5% of the contract’s next $25MM, and 15% of any money above the $50MM mark. So if Imai were to sign a deal matching MLBTR’s $150MM projection, his new team would owe the Lions a $24.375MM posting fee on top of Imai’s $150MM salary.
