BTW if you use the handlebar brake lever it operates both front and rear brakes. The pedal in the right footwell only operates the rear.
650 miles seems low for a failure like that but stuff does happen. Bite the bullet, buy the rotor and change it out. Not that tough. I would avoid the really cheap parts though. You have no idea where they come from (well probably China). Along with questionable quality. Either get a Polaris part or one from a known aftermarket company.
Mine: 2018 Sportsman 850SP - 26" Bear Claw HTRs on OEM steel wheels(I really don't like the Aluminum ones)
Polaris Hand warmers, Mirrors.
Hers: 2019 Sportsman 450. 26" Bear Claw HTRs on Moose 427X Wheels.
2007 Sportsman 500 EFI, Polaris Winch, 25" Bear Claws QSC Clutch Kit, Hand Warmers
2001 Magnum 325 MOSE 12" rear wheel conversion. 25" Sedona Coyote tires
2017 Polaris Ranger 1000XP - Roof and front glass
2018 Kawasaki KLR650
2001 Magnum 325 Warn winch and Moose 60" plow-Sent to Daughter and Son-In-Law since his blew up
SOLD 2004 Sportsman 600 Twin