you didn't ask me, but I'll give you my perspective, Joe.
Ever since I was about 10-12 years old, I've always felt uncomfortable when the national anthem was played. It's hard to explain why; it just didn't feel right. Maybe it was the blind allegiance. Or participation in what felt like "Nationalism" at the same time (early 80s) where we were all told that Nationalism coming out of the Soviet Union was a danger to the civilized world. If it was wrong for them, wasn't it also wrong for us?
Also, I don't want to be told when and how to show my patriotism. I love many parts of this country. Because of this country, my mother -- raped and impregnated at 21. Lied to and impregnated at 24. Drug user (along with various uncles and aunts) -- was given food for her and her children to eat, health care to survive, a stipend to live on (welfare), and eventually a free college education. She went on to be a school teacher for 10 years, and although retired from that, still owns a (somewhat) successful landscaping business and has been paying taxes for the past 25 years. Her kids are now lawyers and college professors. What a country! I am thankful for it every day (or I should be, if I remember to be).
But I STILL don't want to be told when and how to celebrate my appreciation. And I probably would feel even more strongly about it if I was a role model on the field of play.
So - how would I handle it? If I was the commissioner, I'd make it clear that standing for the national anthem was 100% optional. At the VERY least, I'd have extensive conversations with the Players Association -- my employees! -- about this issue, and actually listen to them. I'd make the owners vote me out if they wanted to put their pocketbooks over my conviction (If I'm the NFL Commish, I'm probably rich anyway).