The former UH quarterback is banged up bad, with broken bones and internal bleeding.
Thankfully, his father says the injuries are not life-threatening.
New pictures came in Friday night showing the wreckage from the head-on collision in North Kona.
At about 9:30 a.m. police say Brennan was the passenger in a Toyota SUV driven by his girlfriend when she crossed the center line on Queen Kaahumanu Highway, in Makalawena.
The SUV slammed into a Saab sedan driven by an unidentified Waikoloa woman.
The Saab went airborne landing in a lava field off the road.
The Waikoloa woman was trapped and needed to be extricated.
Brennan's girlfriend got out of the SUV on her own.
But Brennan was stuck inside and needed fire crews to get him out.
He was later airlifted to Oahu for further care.
Earlier in the evening, Brennan's dad had said that his son was in stable condition. But a spokesperson at The Queen's Medical Center actually said Brennan is officially listed in serious.
"He's still under anesthetics and so forth and they're doing some more cat scans. He's got some broken ribs, I believe it's the left clavicle and just trying to monitor his head injuries," said Terry Brennan, Colt's father.
Brennan says his son and girlfriend Shakti Stream were on their way to a volleyball tournament, when stream suddenly swerved into the opposite lane causing the head-on collision that left Brennan trapped in the silver SUV.
"It is undetermined at this time if speed, alcohol, or drugs were a factor in the crash. It's too early to determine if any charges will be filed but we have initiated a negligent injury investigation," said Major Randy Apele of the Hawaii Police Department.
Police say Brennan's 27-year-old-girlfriend, remains hospitalized on the Big Island at North Kona Community Hospital.
Brennan was airlifted to Honolulu and taken to The Queen's Medical Center in an ambulance.
Colt's father says he has yet to speak to his son.
"No, not really, other than the doctors and then before they put him on the Medevac helicopter. I think they were putting him under a little bit, they were giving him some more things to calm him," said Brennan.
Brennan's family was not able to catch a flight on Friday, but they will fly in from California Saturday morning.
Brennan's father tells Hawaii News Now the family is especially concerned about the two women hurt in the crash.
Brennan's longtime girlfriend, Stream, was last listed in serious condition.
The driver struck by Stream's car is a 47-year-old woman from Waikoloa.
She was medevaced from the scene to the North Hawaii Community Hospital in Waimea where she was last listed in serious condition with undisclosed injuries.