The pinion gears rarely have issues. If you did toast the pumpkin, a used one can be had very reasonably.
If you have a lot of play / slop it could be your drive gear is worn. Its a sacrificial wear part that interfaces the rear wheel with the 'pumpkin'. It can wear over time, especially if not lubed properly.
At the end of life, the splined teeth can wear totally smooth and the bike won't move forward in gear, sometimes causing an incorrect suspicion of a clutch or tranny problem.
Its 42034-0002 COUPLING,RR HUB on the parts fiche and is circled in yellow below.
The red arrow shows where the splined teeth are.