What sport could you play the longest in a televised game without anyone knowing you aren't a professional? How long would you last?

I'm going with golf.  I can walk out, tee up, pick a club...  Yeah.  Then I'm busted.

I might last 4 downs in a football game. But after that, with my age, I'd probably be carried off on a stretcher.

I could last an entire pro baseball game, as a bench warmer.