Paolo Di Canio launched an angry attack on the discipline of his squad after Phil Bardsley was pictured laying on the floor of a casino covered in £50 notes.
Bardsley was left out of Sunderland’s squad after the picture of him – taken after the club’s survival was assured on Tuesday night following Wigan’s loss at Arsenal – was printed in The People newspaper on Sunday morning.
Di Canio claims the mentality he has encountered at Sunderland is worse than that of League One side Swindon, who he managed before taking charge at the Stadium of Light.
Bardsley accepted being left out of the squad, and denied that he was drunk at the time.
That did not stop his manager from letting rip at Bardsley after revealing he had fined the defender, and Matthew Kilgallon, who was out with the former Manchester United man, for the incident.
"I saw the picture on a website and moments later he was out of my squad," Di Canio told a press conference. "How can I play a player that probably is blurry for three, four days after what’s happened? I want to deliver a very clear message: there is no excuse to behave like he did. They went out because Wigan lost the game and we stay up.
"I could understand it if we had won the Champions League or maybe the FA Cup. We have to respect the dignity of the club, and the fans. I thought that at Swindon… arrogant, ignorant footballers because they’ve not had many chances to stay at the top level.
"I have to tell you unfortunately I found a worse environment in terms of discipline in this club. This is what I’ve found in the last few weeks so we have to change completely."
Di Canio said he will consider the future of both players after the incident.
The image of Bardsley, laying out on the floor amid swathes of cash caused outrage among football fans who struggle to cobble enough money to attend matches.
Surprisingly, Di Canio has continued to encounter problems with some members of his squad since the players’ night out on Tuesday.
The Italian claimed that one squad member who was left out of his squad for Sunday’s game refused to train back up at Sunderland’s base.
The player in question claimed he had food poisoning, but Di Canio does not appear to believe him.
"Some player that couldn’t involve (himself) in my squad today for a different reason decided: I don’t train today," the animated Sunderland boss said, slamming the table with fury. "They make that diagnosis. He didn’t go to the Academy of Light because he said ‘yesterday I had poisoned food’. Sorry.
"The doctor tried to contact him. His phone was switched off for three hours. This is the situation at Sunderland."
Di Canio revealed earlier in the week that he had fined seven players for indiscipline and he also angrily threatened to cut the squad’s holiday short because of his disappointment with them.
Another outburst against his players may be ill-advised in some people’s eyes, but Di Canio insists he needs to take this action if he is to move Sunderland forward next season.
"Maybe I tell you this and tonight they sack me? I don’t know but if you want to change something you have to follow me," he said. "These players will not be here next year. Not under me. The owner and I are going to sit at the table and go through but he knows many things. I spoke to him before by telephone and he told me we are going to change many things.
"This is what he told me before. (He said) ‘Relax, don’t worry because we are going to change many things’ so it sounds like he supports me completely. We will see in the future."
Some Sunderland players had planned to go on holiday straight after Sunday’s game, which the Black Cats lost 1-0 thanks to Gareth Bale’s late winner, but Di Canio will not allow them to go on their annual leave until Tuesday.
"The next few days we will be together," he said. "Previously some people organized during the week to go from London to Hawaii, Miami… They were thinking about organizing their bags, four or five of them were talking about going together with their wives and girlfriends. Not possible. Today we fly back to Sunderland, our city, as a team. We stay tomorrow together for a sponsors event, then they can go on holiday."