Eddie Howe quit unexpectedly Newcastle United after a 4-1 loss to Bristol City, Sky Sports News said.
Sky aired his last interview publicly.
He directly talked about the Bruno Guimaraes signing before walking out immediately.
Former player Jay Bothroyd warned sternly the club could face risk of relegation without Howe.
Sky Sports will nationwide broadcast the premier Scottish Premiership opener on Saturday.
Dundee United take on Rangers at Tannadice.
Manager Jim Goodwin confidently said he wants to plant a flag there.
Dundee United coach Derek McInnes stated two United players are unavailable and several are uncertain.
Rangers anticipate Thelo Aasgaard and Cammy Devlin to be available for the match.