6:18 PM PT -- Ronnie Hillman's family just released a statement ... saying Ronnie was diagnosed with renal medullary carcinoma, a "rare but highly aggressive neoplasm form of cancer that primarily affects young African Americans with sickle cell trait" back in August.
Hillman has undergone treatment, but it has not been successful. The family says he is being kept comfortable and out of pain in hospice care.
"As a family, we hope beyond hope, and we have faith that can move mountains," the family said. "We also understand that God's will is not always ours; therefore, we as a family subject ourselves to the will of our Almighty God."
"We need your prayers, but we also need your understanding and respect for Ronnie and our family's privacy at this time."
Former Denver Broncos running back Ronnie Hillman, a third-round pick in 2012, is in hospice fighting for his life ... his former teammates said Tuesday.
Orlando Franklin -- who helped block for Hillman for three seasons in Denver -- initially revealed the sad news on his Twitter page ... asking Broncos fans for prayers for the ex-tailback.
"It's not looking good," Wolfe said on 104.3 The Fan on Tuesday. "He has pneumonia and I'm putting it out there just to send positive vibes his way."
Hillman played for the Broncos from 2012 through 2015 -- and helped Peyton Manning and the rest of the team win Super Bowl 50. Wolfe remembered him as a "great football player, great person, great teammate" and "an all-around great dude" on Tuesday.
Really sad news from @OFranklin74 that Ronnie Hillman is in hospice w/ liver complications.