Sunderland were embarrassed on Saturday after Celtic thrashed the Championship side 5-0 in a pre-season match.
The Black Cats are planning a return to the Premier League after a dismal campaign last term and struggled to put up a fight against the Scottish champions as Callum McGregor scored a hat-trick with Jonny Hayes and Stuart Armstrong also netting.
Plenty of Sunderland players were accused of playing below their full capacity last season as they finished 20th and fears that the players do not currently have the club's best interests at heart were confirmed after midfielder Darron Gibson was caught on camera laying into his teammates.
While admitting he was in a drunk state, the Republic of Ireland international said he still wants to play for Sunderland and claimed "too many people are at the club who don't give a f*ck".
The 29-year-old also rattled off a list of players who are not committed to the club, including the likes of Jeremain Lens, who spent last season on loan at Fenerbahce, and Wahbi Khazri, who only made 21 Premier League appearances as David Moyes' side were relegated.
Gibson joined Sunderland from Everton but struggled with injuries during his first season and made just 12 Premier League appearances, but this video will leave Black Cats fans with conflicting opinions of the former Manchester United youngster.
Simon Grayson has taken over from Moyes as the club's new manager and has signed striker James Vaughan, Aidan McGeady and Jason Steele so far this summer.