On the streets of Copacabana, fans from all nations are sporting their jerseys: Lots of Colombians in bright yellow, Chileans in red, sky blue stripes for Argentina, Mexican green, the German tricolor, a trickling of Aussie yellow, and, of course, the ever-present gold and green of Brazil.
You get the feeling that many of these folks brought along just one shirt in their suitcase, to be worn from now until their team is eliminated.
Today, I got in the spirit and pulled out our U.S. kits. I'd been saving them for the game, but it's hard to start up chants of "USA" when you're donning a plain brown T-shirt.
So, I went down to breakfast in the B&B where we're staying, proudly wearing my vintage 1994 U.S. jersey (for those in the know, it's the red-and-white wavy stripes shirt, which is slightly less hideous than the blue-and-white faux denim stars from the same year).
In the kitchen, I found Milton, the 5-year-old son of the cook, quietly enjoying a sweet bun. I greeted him, only to be told that Milton is muito timido, very shy.
Undeterred, I asked him if he liked football. A nod of the head. The Selecao? A more vigorous nod. And how about this one? I asked, pointing to my shirt.
Now, there are a few reactions I expected as possibilities, ranging from an encouraging nod to an uncomprehending shrug. But I never expected what followed. Milton took in my words and rolled his eyes. That's right, my suggestion of victory for the U.S. earned an eye-roll from a Brazilian preschooler.
It seems the U.S. has an uphill climb, but I will be cheering and waving the flag, nonetheless. Viva a Copa!
Matt Kelemen is the soccer-crazy brother of NPR diplomatic correspondent Michele Kelemen.