I *think* it is time of residence that matters, and where the income is earned. All players (Twins and visitors) pay Minnesota income tax on the salary they earn when playing in Minnesota. If they are Minnesota residents for a certain percentage of the year, they are also subject to Minnesota income tax, but the rules are complicated for income earned elsewhere. I'm not a tax attorney or accountant, so I don't know the details. A local example, though: Portland (~9% income tax) is located just across the river from Vancouver, Wash., (no income tax), but if I lived in Vancouver and worked in Portland, I'd still have to pay Oregon tax on my earnings because they were earned in Oregon. But in retirement, I'd get a 9% raise by moving to Washington, as long as I could still buy all my stuff in Oregon where there is no sales tax.