The Secret Footballer has insisted that there are "big problems" at Sunderland, many of which centre around alcohol.
The Black Cats only just fought off the threat of relegation last term and no win from their first five Premier League matches this season resulted in Paolo Di Canio being sacked as manager earlier this week.
Di Canio was heavily criticised for taking a hard line with the Sunderland squad, but The Secret Footballer, who is an alleged pseudonym of a Premier League player, has accused the players at the Stadium of Light of having a poor attitude and a "drinking culture".
"There are problems at Sunderland – big problems. The squad simply aren't good enough on the pitch and, of even greater concern, they have too many players that do not have enough respect for the game," he said. "It is no secret in football circles that there is a drinking culture at Sunderland that extends right through the core of the team.
"I've witnessed it in full swing as I've been in the same places drinking with many of them. I can vividly remember being in Marbella when one Sunderland player ordered a Nebuchadnezzar of champagne for £75,000. Seriously. A waiter bought it out on a trolley and it took three of them to pour it every time he wanted to top up his glass.
"And last season, after the team had been hammered on the Saturday, a friend sent me a picture of half a dozen Sunderland first-team players all holding up cigarettes and pints of beer in a pub during an all-day session on the Sunday."
Gus Poyet is the current favourite to replace Di Canio, although interim boss Kevin Ball is expected to take charge of Saturday's match against Liverpool.