on a TN visa, can i accept sports sponsorships/go pro?

hello fellow expats! would appreciate any advice!

background:
born and raised in Canada, came to the US in 2001 under a F1, graduated in 2005 and have been on a TN as an economist since.

current situation:
on a TN for my job, have been a fairly serious amateur athlete and been competing in amateur competitions for years
as a Canadian and since I'm already here, it's been my understanding that I don't need to apply for any additional visas to compete in amateur competitions...does anybody know if that changes if I go pro?
It is an individual sport (mma) so there's not really one "employer". It'd be the promoters of the individual shows.
Also, does anybody know whether I am allowed to accept sponsorship deals?

Thanks in advance!

You would need a athete's visa (O or P), which would mean giving up TN.

You can't have both at same time.