Matt Herrian thought his broken leg was a big deal. Never came back as the same player.
Ok? This doesn't prove much. The injuries were completely different, it's apples to oranges. Herrian broke both his tibia and fibula, while Fisher broke his fibula. Herrian's was a devastating career-ending type injury. A broken fibula isn't a huge deal, hell Tebow finished a game in high school on a broken fibula. The fibula isn't a weight bearing bone.
Are you saying you think Fisher was better before his injury? I see the same tentative, weak player that he was before.