Michael Gray says Sunderland can no longer be considered a big club and are staring down the barrel of consecutive relegations.
The Black Cats were heavily beaten at the Cardiff City Stadium on Saturday, the hosts running out 4-0 winners after a disastrous second half.
Sunderland are rock bottom of the Championship having scored just two goals in their last seven games.
Other results did at least go in their favour on Saturday afternoon, meaning they remain one win from safety despite this latest embarrassment.
They face Hull City next Saturday, the Tigers currently in 20th position and three points clear in the table, with Chris Coleman admitting that it is crucial he lands attacking reinforcements in the near future.
Gray, appearing as a pundit on Football on 5, said: "We need 28 points to get us to the magic number in the Championship which is 50.
"When you think, we've only got 22 for 28, which is just not enough. We've not been good enough. I think the club is just rotten from top to bottom.
"I think we've got a manager from Waitrose and players who you would buy at Aldi. That's the problem that we've got, you're bringing in loanees that just aren't good enough and the experienced players are making the same mistakes every week. If it doesn't change we're looking at League One. We are not a big club anymore."
Coleman said after the defeat that his players had shown a 'soft mentality' in their second half performance.
"It’s soft, a soft mentality, simple as that, no toughness," he said.
"Toughness isn’t nailing someone in a challenge, putting them on their backs, that is easy. Toughness is mental, that’s what it is.
"Staying strong, making consistently good decisions. We’re going to stay where we are doing that, it’s no coincidence we're at the bottom. We’re gifting goals to teams."