Di Matteo, who won the FA Cup and the Champions League in 2012 after stepping in to replace Andre Villas-Boas, was sacked as Chelsea manager in November of the same year after failing to impress Roman Abramovich with his team's performances both home and abroad.
However, the Mail reports the Italian was unable to reach an agreement with Chelsea's owner over a pay-off, and so continues to collect the salary he once earned at Stamford Bridge.
Neil Ashton, the paper's highly respected football reporter, writes:
"The Italian was unable to reach a settlement with owner Roman Abramovich on his three-year deal when he was fired six months after winning the Champions League as interim boss.
"Di Matteo has already banked almost £7million and will continue to pick up the king-sized salary until June 2014, meaning he is reluctant to take on another job for less money."
Now Early Doors realises why Di Matteo's name quickly dropped off the shortlist for the Sunderland job - why on earth would you give up all that cash when you are being paid to do nothing?
If the Mail's report is correct, then Di Matteo has surely become the managerial version of Winston Bogarde, who famously collected a fat wage package despite barely featuring for the club's first team.
Still, at least Di Matteo is a bona fide Chelsea hero thanks to his successes as both a player and manager.