Sunderland's turmoil after back-to-back relegations has nothing to do with outgoing owner Ellis Short, says former manager Gus Poyet.
The Black Cats will play in the third tier for the first time in 30 years next season, while Short has agreed a long-awaited sale of the club.
"There is something inside the club that doesn't let it be as successful as should be," Poyet told BBC Sport.
"I don't think it is anything to do with Ellis Short."
The Uruguayan said the current situation is "incredible", adding: "It hurts a lot because I had a great time there."
Poyet was one of nine managers during Short's reign but was sacked in 2015 with the club 17th in the top flight.
Short has owned Sunderland for nine years and during his time in charge the club repeatedly escaped Premier League relegation before finally dropping out of the top flight last season as the bottom side, before suffering the same fate in the Championship this campaign.
The American has been heavily criticised in recent seasons for a lack of spending and a distant relationship with the club as he tried to sell - manager Chris Coleman, who was sacked on Sunday following relegation from the Championship relegation, claimed he did not speak to Short during his six months in charge.
'I had a fantastic time'
But Poyet said he has "no complaints" about his relationship with Short.
"We always talked regularly when he was in England, London, Sunderland or in America," Poyet said.
"When you change the manager many times and it doesn't get better, then people blame the directors and the chairman.
"I had a fantastic time with him when I was there. We were always very honest to each other, he knows what I think about everything that was happening there and it is fantastic for him to remember those things I said to him and that will stay between us."
Poyet took charge of Sunderland in October 2013 with the club bottom of the Premier League.
Four victories and a draw from their final six league games helped keep them up - a run that included wins at Chelsea and Manchester United, plus a draw at Manchester City.
The Uruguayan also led the Wearsiders to the 2014 Capital One Cup final, which they lost to City.
Former manager Simon Grayson, who started this season in charge of the club, added: "It's very difficult to solely put the blame on Ellis because he's invested something like £200m into a football club and anybody who invests that sort of money has a real affinity with a club."