I would think the NBA — which plays a game that already has proven to be very popular in Europe — would do this long before the NFL does.
The NBA is already getting the benefits of international popularity. They sell jerseys all over the world, and they pull in talent from all over the world. The NFL is doing OK on the jersey selling, but they’re not pulling the global talent. And given that American Football will never be in the Olympic (which played such a big part in basketball’s growth) or any other international competition if the NFL wants to get audience (and talent) from outside America they need to grow it themselves. That’s really what the American Bowl series (going all the way back to the 80s) has always been about.