Former NFL quarterback and current analyst Mark Sanchez is facing a felony charge for his role in an altercation that led to the former New York Jet being stabbed early Saturday morning in the US.

Marion County, Indiana, prosecutor Ryan Mears said Monday that further investigation by police led to the more severe charge.

Sanchez had initially been charged with three misdemeanours as a part of the incident. Mears said he now faces a charge of felony battery involving serious bodily injury, which carries a maximum sentence of between one and six years in prison.

According to Mears, the dispute between Sanchez and a 69-year-old truck driver began over a parking space.

“You have the allegations of a 38-year-old man becoming involved in an altercation with a 69-year-old man who sustained significant, very severe injuries as a result of that altercation,” Mears said.

“… We are literally talking about people fighting over a parking space and/or a dispute about where people are parking, and it resulted in just incredibly significant injuries.”

Perry Tole, the 69-year-old man involved in the incident, filed a lawsuit against Sanchez and Fox Corporation in Marion County on Monday. Tole and his attorneys allege civil counts of assault/battery and negligent hiring, retention and supervision. The lawsuit does not seek a specific amount of damages rather it asks for the amount awarded to be determined at trial.

Nick Sanchez, the brother of Mark Sanchez, issued a statement on Monday on behalf of the Sanchez family.

“This has been a deeply distressing time for everyone involved. Mark and our family are incredibly grateful for the concern, love, and support we’ve received over the past few days,” the statement read.

“Mark remains under medical care for the serious injuries he sustained and is focused on his recovery as the legal process continues. We would like to extend our heartfelt thanks to the first responders and medical staff.”

Sanchez was in Indianapolis to work as an analyst on Fox Sports’ broadcast of the Indianapolis Colts game against the Las Vegas Raiders on Sunday. An affidavit seen by CNN said that Sanchez was initially taken to a local hospital in critical condition in the early hours of Saturday morning. Fox Sports reported on Saturday afternoon that Sanchez was in stable condition.

Mears said an updated affidavit was submitted by police that contained more details which subsequently led to the felony charge.

CNN Sports has reached out to an attorney for Sanchez for comment on the allegations.

Indianapolis Metropolitan Police chief Chris Bailey said, “We’re lucky that no one’s dead right now as a result of this incident that involved a knife.”

According to a new affidavit filed Monday, Sanchez was running in an alley near the Indianapolis Marriott Downtown when he approached the 69-year-old man. Tole works for a company that exchanges commercial frying oil and was parked in a loading dock area of a hotel.

Detectives reviewed surveillance footage from the Indianapolis Marriott Downtown, which captured the incident and showed Sanchez approaching Tole’s truck and beginning a conversation, the affidavit said. CNN has reached out to the hotel to review the footage.

Tole told detectives that Sanchez – whom he did not recognise – smelled of alcohol and was slurring his speech.

He also said that Sanchez had climbed up into the cab of the truck despite Tole insisting he should not enter. The footage reviewed by detectives showed Sanchez grabbing Tole throwing him up against a wall.

Tole told detectives that he pepper-sprayed Sanchez and, when Sanchez continued to advance toward him, Tole pulled out his knife and struck Sanchez several times.

According to the affidavit, Tole was quoted saying, “This guy is trying to kill me.”

Tole told police that he took out his knife and stabbed Sanchez two or three times and then fell into the dumpster and some pallets that were on the ground. He said he felt he was in a life-or-death situation as Sanchez was on top of him, before eventually getting back to his feet.

“Somehow, (Tole) made it to his feet, and when Mr Sanchez came at (Tole, he) stabbed Mr Sanchez the last time. The next thing (Tole) knew was Mr Sanchez looked at him with a look of shock, he slowly turned around and Mr Sanchez took off northbound in the alley,” the affidavit states.

The lawsuit states that the truck driver was “bleeding profusely and severely injured” after the incident. The suit adds that Toler suffered “permanent disfigurement, loss of function, other physical injuries, emotional distress and other damages.”

The lawsuit accuses Fox Corporation of not supervising Sanchez’s behaviour and that it should have known about his “propensity for drinking and/or harmful conduct.”

Sanchez later told a detective that he could barely remember anything from the incident, and that he did not know who it involved or where it happened.

Police were called to the Loughmiller’s Pub and Eatery on W Washington St, less than a mile from the Colts’ Lucas Oil Stadium, and found Sanchez with several stab wounds to his upper torso, the affidavit said. They also located a second man with a laceration to his left cheek.

Prosecutors have lots of video evidence regarding the incident, Mears said Monday. That evidence could lead to more charges down the line.

“Where this incident took place was an area of the city which was very well covered by surveillance footage,” the prosecutor said.

“There are multiple angles of surveillance footage which capture the events that occurred. And in addition, we had a number of civilian witnesses who came forward with provided information about what took place for us, though we need additional information, and chief’s team is working on that.

“And once we receive that additional information, additional charges might be appropriate to file in a case like this.”

Among the initial misdemeanour charges filed against Sanchez was public intoxication. Bailey declined to answer a reporter’s question about the former quarterback’s blood alcohol level, but said the investigation is ongoing.

“Just because charges are filed doesn’t mean the case or the investigation stops, so the investigators will be looking to all those things,” Bailey said.

“And I think the medical records are going to be extremely important for both individuals to help the prosecutor make a charging decision – to see if there’s another charge that needs to be added, but also to see if there’s if there were some sort of altered state of mind of the individuals involved in this incident.”