Former Real Sociedad boss David Moyes
The Black Cats performed yet another miraculous escape from relegation last season, with Allardyce leading them to safety - but that success now appears to be luring Allardyce away from the Stadium of Light.
Reports from BBC Sport claim that Allardyce, 61, is set to be named the new England manager following Roy Hodgson's departure earlier this summer, leaving Sunderland with a huge hole to fill in the dugout.
Sunderland have tonight released a statement admitting their 'anger and frustration' as the confusion around Allardyce's future continues, but with a deal seemingly close, it's time for Sunderland to weigh up possible replacements for 'Big Sam'.
Sunderland manager Sam Allardyce
Now, The Mirror report that preliminary talks have been held with David Moyes about succeeding Allardyce, with the Scot seemingly Sunderland's first choice target.
Moyes, 53, has been out of work since his underwhelming spell at Real Sociedad came to an end in November, and the former Everton boss desperately needs to rebuild his career having failed at both Manchester United and then Sociedad.
It's claimed that, having spoken to Sunderland about a move over the weekend, Moyes is ready to accept a route back to the Premier League with the Black Cats.
The report adds that Moyes is highly regarded by Sunderland's owner Ellis Short and new chief executive Martin Bain, making him the strong favourite to take over from Allardyce - but concrete moves will only start once Allardyce's expected departure is confirmed.