TMZ:
Jabari Parker just told the world he'd contracted coronavirus -- and less than 3 days later, the guy doesn't appear to be in isolation ... but rather, he's playing tennis in public.
The Sacramento Kings star was spotted Saturday in Chicago's Longfellow Park, where he was rallying with a buddy on the other end of the net ... all smiles, and without a mask. Mind you, he'd just announced a few days earlier that he had test positive for COVID-19.
Another somewhat troubling sign -- sources tell us Jabari was recently seen out at a restaurant there in the Windy City.