Eddie Howe quit suddenly Newcastle United after a 4-1 loss to Bristol City, Sky Sports News said.
Sky aired his last interview briefly.
He openly talked about the Bruno Guimaraes signing before walking out right after.
Former player Jay Bothroyd warned sternly the club could face risk of relegation without Howe.
Sky Sports will nationwide broadcast the national Scottish Premiership opener on Saturday.
Dundee United take on Rangers at Tannadice.
Manager Jim Goodwin firmly said he wants to make an impact there.
Dundee United coach Derek McInnes stated two United players are unavailable and several are in doubt.
Rangers anticipate Thelo Aasgaard and Cammy Devlin to be in form for the match.