Martin Bain believes a 'fundamental change' was needed at Sunderland to stop them from dropping into League One.
The Black Cats parted company with manager Simon Grayson last night just minutes after the 3-3 draw with fellow Championship strugglers Bolton Wanderers at the Stadium of Light.
The result left the Wearsiders in the bottom three, with Grayson having just won once in 15 league games since taking over the reins from David Moyes in the summer.
And while praising the hard work Grayson and his assistant Glynn Snodin put in to the club, chief executive Bain said results on the pitch weren't befitting a club of Sunderland's stature.
Bain, who only unveiled Grayson as manager four months ago, said: "Simon and his team have worked tirelessly to achieve the best for the football club during their time here.
"While we hoped that Simon's experience in the Football League would help us to a successful season, results have not been good enough for a club of this stature.
"In order for us to improve upon our current position we believe a fundamental change is necessary."
Former Sunderland striker Kevin Phillips has been installed as the early favourite with bookmakers for the job, with the likes of Peter Reid, Kevin Ball, John O'Shea and Aitor Karanka all high up in the betting.
Odds: Phillips 4/1; Reid 6/1; Karanka 7/1; O'Shea 8/1; Ball 8/1; Keane 12/1; Moyes 12/1; Allardyce 12/1; Heckingbottom 16/1; Lambert 16/1; McCarthy 16/1; McCoist 20/1; McLeish 20/1; Bould 20/1.