Hassaine, who left Newcastle to play for 5under1and and also spent time at Premier League sides Tottenham and Fulham, left one of his victims fighting for life after stabbing him in the neck.
As the 18-year-old was sent to a young offender institution for wounding with intent and robbery, he wrote to the court telling how he “messed up”.
Hassaine, wrote: “I’m sorry for being so irresponsible, I’ve learned a hard lesson and a lesson which is putting a lot of people through pain.
“I’m trying to be a better man, I would like to show the world I’m not a dangerous person. I’ve messed up and I’m deeply sorry.”
Hassaine had been out drinking in Newcastle armed with a knife.
He became involved in a friend’s argument with Daniel Adah over a mobile phone, pulled a knife and stabbed Mr Adah in the stomach around 1.30am in Chinatown’s Stowell Street area.
Hassaine then went to nearby Tiger Tiger in The Gate (pictured right) and was seen on CCTV leaving with Aguinaldo Neto and others.
Newcastle Crown Court heard Hassaine and Neto approached Fiston Martins outside The Gate and offered to sell him some cannabis.
When Mr Martins got his wallet out Hassaine and Neto saw he had £200 so attacked and robbed him.
After the attack Mr Martins followed them and demanded his money back but was attacked again.
He walked off but was followed, bundled into a fire exit of Asper’s Casino on Stowell Street. Hassaine pulled his knife and stabbed him to the chest and back before Hassaine and Neto walked off.
But when Mr Martins followed again, Hassaine plunged the blade into his neck, causing a life-threatening injury.
He was left needing emergency surgery and fighting for life.
Sentencing Hassaine, Judge Paul Sloan QC said: “He fell to the floor bleeding heavily from multiple wounds and you ran off, leaving him lying in a pool of blood on the pavement.
“Salim Hassaine, I note your efforts to develop your career as a footballer and the effect a custodial sentence will have in that regard.”
Hassaine, 18, of no fixed address, pleaded guilty to wounding with intent on Mr Adah and robbery of Mr Martins and was locked up for eight years.