Nerfed?
Naruto is not Nerfed... do you know what Nerf is?
Naruto is still as strong as ever, he just doesn't want to attack Sasuke, he wants to negotiate.
nerf
To weaken or make less dangerous. Taken from the "Nerf" brand name, which makes sports equipment toys out of a soft foam (e.g., the Nerf football is soft foam rather than the hard leather of a real football). Used frequently in the context of computer game balance changes.
Thats exactly whats going on here. When your not going all out, your essentially nerfed.
Based on the previous feats of Naruto who could have easily turned Sasuke into cinder and ashes
Lest you forgot the 6 bijuu bombs that he spawned