If you jack up the wheel so it is off the ground and give it a wobble, if there is any play you would probably feel it.Could be worn pads, stone or mud caught somewhere,especially if you have been off road.The mud shield may be catching.I would just have the wheel off and give it a visual check.
I had a horrendous noise under my motor the other day,feared the worst, turns out i had a branch caught on the exhaust.....
:oops: