Yes, because frankly hard-anodised aluminium is a terrible material for something small with sharp edges that has wear and tear - would much prefer durable plastic! I dropped my iPhone 5 from one foot at the weekend (while trying to put it in the lower pocket of golf bag) - it now has two wrecked corners to go with many chips that seemingly come from nowhere! :\
Maybe you shouldn't be carrying your phone in your golf bag? That seems like an odd choice to me. Wouldn't it be getting banged up in there, amongst the golf balls, tees, and cleat tools and whatever else you have in there?. Could you even hear it if it rang?
If you don't plan on using it, why not simply leave it in your vehicle or club house locker?