User blog comment:Ichigostop/maybe? usopp?!? maybe not?/@comment-3242083-20101216133445

I don't think he ate one, he is just not at Sanjis level (especially since he learned blue walk). Chopper and Luffy are unconscious for the reason you mention - devil fruit.

I say Usopp is still a "weakling" by physical means, even if he trained hard the last 2 years. Im sure he learned a lot of new fantastic tricks, but they wont make him dive in 10.000 mile deep sea