Headbands! You can make them manly...
My boyfriend watches basketball and while a lot of them wear those terry sweat bands some of them wear a thin elastic headband.
This isn't a very flattering photo (he looks a little greasy lol) but you get the idea....
and if you meet any protest you can always say "but professional athletes wear these!" lol
Actually a terry sweat band might be retro and cute...very "Ritche Tenenbaum"