Sadly, these are areas where Polaris could do a better job it seems. How many miles? Do you live in the mud?
To check the bearing you will have to jack up the machine and check for play between the spindle and knuckle area. This is usually done by placing your hands at the 12 and 6 o'clock position on the tire and trying to move the top in or out. Since you have other bad parts, this may be hard to see or detect. It might be helpful to watch the inside area where the CV goes through the knuckle. If the CV outer joint shaft where it goes through the knuckle moves independently of the knuckle, you have bad bearings. Sometimes you can feel roughness as well, but that would be hard to judge with everything still together. The play is the real giveway.
This video at 44 seconds shows what i am trying to describe...
This one isn't real bad, and your other worn parts may make it hard to determine exactly whats moving.
