Is it possible to merge two sprites in Unity?

I am making a 2d customizable character. I want to go with sprite based animations. So I have created different parts that can be customized. For example eyes can be swapped by different types of eyes by just changing the sprites of sprite renderer. This works fine with still images but does not with animations. I want to merge the sprite of base player with the sprite of an eye to make a single sprite. So I have two sprites and I want to make one sprite out of that and then let the sprite renderer render that sprite. Is it even possible? If so, how?