Manchester United legend Roy Keane could be on the verge of a sensational return to management with Sunderland.

The 50-year-old Irishman quit as boss of the Black Cats more than 13 years ago and hasn't held a head coaching role of any kind since being sacked by Ipswich Town in January 2011.

Despite his long absence between managerial posts, a report from the Daily Mail states that Keane is due to meet with Sunderland sporting director Kristjaan Speakman and owner Kyril Louis-Dreyfus about the vacancy - which was created when previous boss Lee Johnson was dismissed at the end of last month.

Although Keane has become most famous in recent times for his outspoken punditry, the former Republic of Ireland captain has occupied a variety of assistant manager posts since he departed Portman Road.

In one such role, Keane spent just shy of five months working alongside Paul Lambert at Aston Villa.

Former England international forward Gabby Agbonlahor was part of the Villa squad that Keane helped coach between July and November 2014 - and it's far to say that the frontman was not impressed with what he saw.

MANSFIELD, ENGLAND - JULY 17: Aston Villa manager Paul Lambert and assistant Roy Keane look on during the pre-season friendly match between Mansfield and Aston Villa at the One Call Stadium on July 17, 2014 in Mansfield, England. (Photo by Michael Regan/Getty Images)

"The problem with Roy Keane was that when he came to Aston Villa, he couldn’t understand that we weren’t as good as the players he played with," Agbonlahor revealed during a recent appearance on talkSPORT.

"He couldn’t accept that we weren’t going to be as good as Ryan Giggs, Paul Scholes, David Beckham and those players."

The ex-Villa man also expressed doubts as to whether Keane's coaching style would work with modern day players.

"Just his way of coaching, it wasn’t the right method for players nowadays, for players when he was at Aston Villa.

BIRMINGHAM, ENGLAND - NOVEMBER 24:

Roy Keane assistant manager of Aston Villa looks on from the bench prior to the Barclays Premier League match between Aston Villa and Southampton at Villa Park on November 24, 2014 in Birmingham, England. (Photo by Matthew Lewis/Getty Images)

"The way he spoke to players. There were times when there were quite experienced players, people like Joe Cole, and he didn’t speak to them right.

"He spoke to them in a way that was disrespectful. His man management would be zero out of 100. It was that bad."

Agbonlahor then went on to recall a training ground exchange between himself and Keane, shortly after which the no-nonsense veteran quit the club.

"There was a time in training when we were doing a shooting drill. Imagine all 22 players doing a shooting drill, you’ve got to pass it to five players before you get a cross in.

"We hadn’t had a shot for 11 or 12 minutes, you are going to be getting cold and frustrated, so the standard wasn’t very good.

STOKE ON TRENT, ENGLAND - AUGUST 16: Aston Villa manager Paul Lambert and assistant manager Roy Keane give instructions to their team during the Barclays Premier League match between Stoke City and Aston Villa at Britannia Stadium on August 16, 2014 in Stoke on Trent, England. (Photo by Clive Brunskill/Getty Images)

"The gaffer, Paul Lambert, calls us in and Roy Keane is there as well. Lambert says the standard isn’t good enough.

"Me, as captain, I had to come forward and back the players saying we only get one shot every 11 or 12 minutes and we need to do something different.

"Roy Keane comes forward and says ‘oh, are you cold? Do you want another warm up?’

"I said, ‘I’m not talking to you, Roy. I’m talking to the manager’. He gave me that evil stare and the next day he left.

"At that time at Aston Villa, he left because of me.

"I was at Villa for so long. I was captain and it was my club, I wasn’t going to let anyone come in and try to bully me at my club.

"Afterwards, even now, I’m happy it happened," admitted Agbonlahor.

Watch: Gabby Agbonlahor's damning assessment of Roy Keane's coaching skills

"That was six or seven years ago, you can’t speak to players like that anymore," he continued. "You are going to lose them.

"You’ve seen managers in the Premier League do it and end up leaving. 

"His way of management I just don’t think is right. It’s alright on Sky when you can hammer people."

ALBUFEIRA, PORTUGAL - JULY 23: Sunderland manager Roy Keane looks on during the pre-season friendly match between Victoria and Sunderland at the Estadio Municipal de Albufeira on July 23, 2008 in Albufeira, Portugal. (Photo by Jamie McDonald/Getty Images)

In closing, Agbonlahor fired a direct warning to those in charge at Sunderland considering recruiting Keane once more.

"If I’m a Sunderland owner I would be thinking twice. He might go in there and make them even worse.

"If you are a player now, especially a young player, you give the ball away in training and some of them need an arm around them. Roy is the sort of player who will say ‘you are rubbish, get out of here’.

"He doesn’t speak to players in the right way. Yes, one of the best midfielders in the Premier League but that doesn’t make you a good coach or manager."

Quiz: Football mascots quiz: Can you name the weird and wonderful characters at British clubs?

Brutal stuff from the former Villa favourite. All signs, however, point towards Keane getting another opportunity in the Stadium of Light dugout - particularly after bookmakers suspended betting on him taking over earlier this week.

There could be some very interesting times ahead on Wearside.

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