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 openly talked about the Bruno Guimaraes signing before walking out immediately.
Former player Jay Bothroyd warned vocally the club could face danger of relegation without Howe.
Sky Sports will exclusively broadcast the top‑flight 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 confirmed two United players are missing and several are in doubt.
Rangers look forward to Thelo Aasgaard and Cammy Devlin to be in form for the match.