Police said on Wednesday they had interviewed Newcastle players Lee Bowyer and Kieron Dyer after their on-pitch brawl during an English Premiership game earlier this month.
Bowyer and Dyer exchanged blows in front of 52,300 spectators at St James' Park in Newcastle towards the end of their 3-0 defeat by Aston Villa on April 2.
The incident, which resulted in both players being sent off, was also witnessed by millions of television viewers.
"Two people involved in a incident on the pitch at St James' Park on April 2 were interviewed yesterday under caution by Northumbria Police officers," a police spokeswoman said.
"A file is now being prepared for the Crown Prosecution Service."
Lawyers at the CPS will decide whether criminal charges should be brought against the pair.
The English Football Association (FA) said on Tuesday Bowyer had admitted a charge of violent conduct over the incident.
The 28-year-old midfielder has requested a personal hearing which will be heard by an FA disciplinary commission on Friday.
Bowyer, who has one England cap, was fined a club record six weeks' wages by Newcastle and is serving a four-game suspension following the incident.
That ban could be extended at Friday's hearing and he could also be fined by the FA.
The FA rejected Newcastle's appeal against Dyer's red card and he is serving a three-game domestic suspension. He was not fined by Newcastle.