Mari joined Italian side Monza on a season-long loan from Arsenal in AugustArsenal defender Pablo Mari has said he was "lucky" as he prepares to undergo back surgery after being stabbed in a supermarket near Milan.
Local media reported that a 30-year-old cashier died and at least five others were injured after a man started attacking people in Assago.
A 46-year-old suspect was detained by police at the scene.
"Today I was lucky, because I saw a person die in front of me," Mari, on loan at Monza, told Italian media.
Newspaper Gazzetta dello Sport said Spanish defender Mari, 29, had been walking around the supermarket with his wife and son when he was stabbed in the back.
Italian outlet Corriere della Sera reported that former Napoli player Massimo Tarantino was among those who immobilised and disarmed the attacker before police arrived.
"I'm not a hero. I didn't do anything special," 51-year-old Tarantino is quoted by the paper as saying.
Mari's injuries are not life-threatening with his agent Arturo Canales telling the BBC on Thursday that the player was conscious and no vital organs had been affected.
Mari will undergo surgery on damaged muscles on Friday.
"Pablo is an amazing guy," said Monza president Adriano Galliani, who visited Mari along with the Serie A side's head coach Raffaele Palladino, told Gazzetta.
"He had the strength to joke and tell me that he will be back in training on Monday. I brought him greetings from [club president Silvio] Berlusconi and everyone else.
"His team-mates wanted to come here but obviously it was not possible."
Mari joined Arsenal from Brazilian side Flamengo in January 2020 and played 19 times for the Gunners before joining Udinese on loan at the start of the year.
He was then loaned to newly promoted Monza in August.
Speaking after his side's Europa League defeat by PSV Eindhoven on Thursday, Arsenal boss Mikel Arteta said: "I just found out. I know Edu [Arsenal technical director] has been in touch with [Mari's] relatives. He's in hospital but he seems to be okay."
