Lance's body was discovered at his Studio City home Friday morning around 9:30 AM. His cause of death is currently unclear, but law enforcement sources say it appears to be natural.

Lance had been doing a press tour for the fourth installment of the 'John Wick' franchise -- he plays Charon in the movie -- and had a guest appearance scheduled for next week on Kelly Clarkson's show.

Lance posted a selfie video on social media Wednesday morning, appearing to be at home with his dogs instead of attending the 'Wick 4' premiere in New York City ... though he never mentioned why he wasn't going to the premiere.