Rear suspension on modern sports machines, as you will be aware, has a good pasting when ridden hard! The deterioration with the handling is gradual until it suddenly falls off a cliff (metaphorically speaking of course!) - before it does make that transgression, an overhaul may be a case of a stitch in time saves nine?
This part and the others listed below are just some of the wear items you may choose to replace:
390070006
391110057
420361258
920461272
920491223
921530508
420361342
922101139
420361360
920461273
920491225
920491493
921531546
It is not recommended to interface old worn items with new in this assembly. Do not forget to order all the fasteners you will require to ease the reassembly process and because new fasteners just look nicer!