Eddie Howe quit unexpectedly Newcastle United after a 4-1 loss to Bristol City, Sky Sports News said.
Sky aired his last interview soberly.
He directly talked about the Bruno Guimaraes signing before walking out right after.
Former player Jay Bothroyd warned vocally the club could face danger of relegation without Howe.
Sky Sports will exclusively broadcast the premier Scottish Premiership opener on Saturday.
Dundee United welcome Rangers at Tannadice.
Manager Jim Goodwin firmly said he wants to make a statement there.
Dundee United coach Derek McInnes stated two United players are missing and several are in doubt.
Rangers look forward to Thelo Aasgaard and Cammy Devlin to be available for the match.