Reid supports Keane's abrasive attitude, however, saying it's the players who need to change rather than the now Nottingham Forrest assistant manager.

"Roy is demanding. He demands high standards and you need to be mentally strong working with him," Reid told talkSPORT.

"I don't see any problem with that. People are saying you can't treat people like that anymore. What? You can't demand high standards?

"You can demand high standards. Day in, day out. Pass the ball probably. Ten-yard pass, make sure it's done probably. There's a tackle there to be made, tackle. Do it properly.

"I don't see anything wrong with that and if people can't deal with that, then they need to work on their personalities."

Reid's final international cap came in O'Neill and Keane's first game in charge of Ireland, a 3-0 friendly win over Latvia in 2013.

He said Keane has had to adjust to the role but expects him to prove a success as a coach.

"I was in two or three squads with him before I got injured and it is a different dynamic for Roy. He's not the manager.

"Although he's going to let you know his opinion, there's times when he has to step back, and there's times when he has to be the one going up to people and having that quiet little chat with them.

"But if Roy Keane is coming up and having a quiet little chat with you, you're going to respond to it. I'd say Roy is one of the best players I played with because whenever he came into a team, everybody in the team raised their game by 1 or 2%.

"Not because of anything he did on the ball, because he was there, because of his personality.

"If everybody in the team raises their game by 1 or 2%, your team is going up 10 or 20% in your performance. I've never experienced another player have that effect on a team before.

"Roy is probably still finding his way to do that in management and in coaching. When he does, I think he can be very, very successful."