Have you lost your frame plug on your Suzuki DR650? Or maybe a passenger accidentally kicked it off with their boot?
 
Whatever the reason, those frame plugs help keep the water and grit away from the long axle behind it.
 
This is the small upper left one, covering the motor axle mount.
 
This is a Suzuki Genuine Parts:
43586-32E00-000 PLUG, FRAME BOSS