Former Sunderland manager Martin O'Neill has warned the Premier League strugglers they might regret the decision to sack him.
O'Neill was dismissed by the club's American owner Ellis Short just hours after last Saturday's 1-0 home defeat against Manchester United.
Sunderland have gone eight games without a win in the Premier League and are dangerously close to the relegation zone.
But O'Neill, who has since been replaced by former Swindon boss Paolo Di Canio, is convinced he would have kept the Black Cats in the top-flight if he had been allowed to remain in charge.
The former Aston Villa and Celtic boss had already inspired a Sunderland team bereft of confidence and languishing in 16th place when he took over in December 2011, guiding them to a 13th-placed finish.
"I am still pretty disappointed, frustrated as much as anything else but life goes on," O'Neill told BBC Radio Five Live on Friday.
"I'm in the business now where I think very little shocks you about professional football especially in the last 10 years. You can lose a job in management if your tie doesn't fit your suit.
"With the experience I have had over the years, also coming into the football club at a time when the club was pretty well on its knees, I believed I saved it from relegation last year and I thought that opportunity should still have been afforded to me."