The original proposal was that star athletes attempt to negotiate tax incentives with cities, in the same vein Amazon did with NYC (and many other large corporations do).

City income taxes add a trivial percent to the total income tax rate when compared to the state income tax level. Thus, if you got incentives from a city, they would amount to trivial amount of savings.

Athletes would need to negotiate at the state level in order to have a material effect on their taxes.

I hope that clarifies my point.

I imagine Athletes pay accountants who are well versed in how to fill out those forms, and, at least in the NFL's case, a lot of players compensation may be in bonuses, and not necessarily game-day checks (which would be subject to local jurisdictional income laws).