The Republic of Ireland assistant manager was sacked by Black Cats owner Ellis Short in 2008 and has hit out at his former club following the Dutchman's departure.
Roy Keane has hit out at the Sunderland hierarchy following Dick Advocaat's resignation as manager.
The experienced Dutchman left his position at the Stadium of Light after the 2-2 draw with West Ham at the weekend, a result which left the club without a win from its first eight Premier League matches.
Former Sunderland boss Keane was asked for his view on the situation as he spoke to the press ahead of Republic of Ireland's crucial Euro 2016 qualification tie against Germany and did not hold back in an apparent dig at owner Ellis Short, who sacked him in 2008.