Just like Buckshot said, I would clean it up and see how it looks. If it cleans up perfectly, install a new seal and be done with it. If in doubt, install the sleeve, but only after you have cleaned it very well. It should not be difficult to clean and keep the debris out of the bearings. This is not as big of a problem as it may first seem. It is highly unlikely that you will need to pull the crank out.
