Ariens 28"Hydro Impeller Issue

Purchased the 28" Hydro a couple years ago and this is my second year using it. When I started it up for the first tie this year it was making a scraping (metal on metal) sound. I was still able to use it and when I was looking at it afterwards the back plate behind the impeller showed clean exposed metal. When I use my hand to turn the impeller is looks like one blade is scraping the back plate. Is it possible that the impeller is off balanced or just one blade is bent and is that fixable or am I just going to have to deal with it? I never hit anything or sucked anything up that would have bent it so not sure how this happened for a 2 years old Ariens.