If the Mets wait another couple of weeks to call him up, the Mets will have Rosario under their control through 2023. If they wait another 12 months, plus a week or two, they'll have him under control through 2024. You're mixing up arbitration eligibility with FA eligibility. The qualifications for each are different. FA requires six full seasons of ML service time with a full year of service time defined by anything within I think it's 12 days of a full year. The full ML season is, for accounting purposes, 182 days long and players get a day's worth of credit for every day they're up with the big boys. So if Rosario were to be called up tomorrow and never spend another day in the minors he'd end the 2022 season with 5 full years of service time and about 20 days short of his sixth, but it might as well be 150 days short because, either way, he won't qualify for FA-gency until the end of 2023 Arbitration is different in that while everyone with three years of ST qualifies and no one with only two years does, about 1/6 of those* with more than 2 but less than 3 also qualify, obviously the percentage of those with the most. So 2 years plus 150 days guarantees it and 2 years plus only a handful doesn't, those in between are in the gray area with no set amount since it depends on how they compare to each other. If the Mets are going to turn to Rosario because Asdrubal goes down or something I don't think the arb situation would matter to them much. The FA date is different as in what the Cubs did with Kris Bryant a few years back deciding that he needed more "seasoning" until calling him up on April 17, 2015. That move pissed Scott Boras off to no end and everyone knew what the Cubs were up to with their decision that he "wasn't ready" on opening day, but there was nothing they could do about it. FA is obviously the much bigger deal. All delaying Arb does is make the theoretical Year 3 contract less expensive by keeping it under direct team control. And while that's not something those in charge of budgets want to ignore, it has no effect on how long a team can control the player and really only affects the salary for that one year, and even that can be negated by a long-term deal buying out the arb years if the player is any good or not caring if he turns out to suck. * I think they altered this slightly in the last CBA, so that pct may not be exact. oe: it's now 22% - so say if in a given year there were 50 players with > 2 but < 3 years of service time, the 11 with the most time would be arb-elgible regardless of exactly when they were first called up or how they accumulated that time