Carlos Edwards while playing for Sunderland

Roy Keane will send ‘shockwaves’ through Scottish football if he is appointed Celtic’s new manager. That’s according to Carlos Edwards, who played under the Manchester United legend at both Sunderland and Ipswich.

Despite not managing a club since leaving Ipswich in 2011, Keane is one of the bookmakers’ favourite to succeed Neil Lennon at Celtic, who surrendered their Scottish Premiership title to Steven Gerrard’s Rangers this season.

And Edwards, who was signed by Keane for Sunderland in 2007 before linking up with him again at Portman Road two years later, has backed his former manager to be a hit in Glasgow.

“If Roy gets the job, give him time, that’s all he needs to be successful,” he told talkSPORT.

“It would be massive. All you’ve got to do is look at Stevie G at Rangers. He’s been in the job for almost three years and you can see the big change.

“Now, with a new face and a new challenge coming into that Scottish league, it would be even bigger.

“Roy Keane vs Steven Gerrard, who had battles with each other for Manchester United and Liverpool, that would send shockwaves through Scottish football.

“He would get the backing of the fans there. He’s been out of management for a long time, but I don’t think it would be a concern because he is a football man.

“He knows the ins and outs, he’s played at the highest level. He’s been an assistant to Martin O’Neill [at Aston Villa, the Republic of Ireland and Nottingham Forest].

“So just being around football for such a long time, I don’t think it would be beyond him.”

Keane guided Sunderland to the Premier League in the 2006/07 campaign, before leading the Black Cats to a 15th-placed top-flight finish.

The Irishman resigned from his role in December 2008, but jumped back into management with Ipswich four months later where he signed Edwards for a second time.

Edwards revealed his teammates used to up their games in training due to Keane’s accomplishments as a player, which saw him win seven Premier League titles.

The former Trinidad and Tobago midfielder said: “He used to join in on the training sessions quite a lot. He used to love that.

“He used to take the mick out of some of the guys sometimes because he still had those touches.

“By him joining the training, it gave the guys that extra spark to impress him a bit more. That was a good sign.

“Sometimes he’d just sit back and watch the training and have his second in command and first-team coaches do a bit.

“When it came to the nitty, gritty side of it, making sure everything is solid and secure in team selection, he was the man at the forefront.”

But Edwards, who now plies his trade with non-league club Bury Town, admitted Keane went ‘overboard’ with his criticism of players at times.

He added: “I got a few bollockings for messing up in games and causing a few goals, but I never got the brunt of it.

“Roy had his moments when he let a few steams out, which is understandable.

“He went overboard at times, but as a player you had to sometimes take it on the chin and just try to move on.

“When emotion gets the better of you, which happens to most people, a few words were said.

“In my career with him, I never saw him physically go at anyone, but words can hurt a lot. There were times he could have dealt with things in a different way.”

Edwards recalled how every player had to always be on their ‘A-game’ under Keane.

“There were always tough moments because every player had to be on their game,” the 42-year-old added.

“If training started at 9am, he would like you to be at training maybe an hour before, he’d like you to socialise with your teammates and have a bit of breakfast.

“The guys bought into the philosophy he brought in because you’re only seeing each other for a short space of time during the day, but he wanted us to be more connected on and off the field.

“Everybody had to be on their A-game when it came to him, not just in games, but in training, in the way you carry yourself, because you’re not just representing a Roy Keane player, you’re representing the club.

“So he made those things very, very clear to the players.”

Keane is often seen dishing out harsh truths as a television pundit on Sky Sports. And Edwards insists what viewers see on television is exactly what you get in person.

He explained: “Roy was very hard to read. He had a good pokerface. I always say to people what you see on the television with Roy is exactly the way he is in person.

“He’s not changing for anyone. He will tell you it as it is and go about his business.”