Mowing BX2200 - missing shaft boot

[ConcordBX]

After mowing our field, I noticed a rubber boot/shaft seal lying in the grass. I have a BX2200 with a 54" MMM and bagger. I checked the front axles and the axle boots appear to be okay. Does anyone know where this might have come from?

 

[anthonyv]

Check your drive shaft, after a few years they tend to dry rot & fall off