DUBLIN -- Roy Keane believes the influence of managers in the modern game is hugely overrated, and suggests the characters he learned most from during his decorated playing career were his teammates.

Since ending his own playing career in 2006, Keane has had spells in charge of Sunderland and Ipswich and is currently an assistant coach with the Republic of Ireland national team and Premier League side Aston Villa.

However, the former Manchester United captain says the tacticians on the touchline do not deserve the attention they receive.

"Managers get too much credit and they also get too much criticism when things go wrong," Keane said at the launch of his new book in Dublin.

"The lads I played with at United were great, great lads. The days I had with them were the best days of my life. For people to try and tarnish that, have little digs, you have to come out fighting. Enough is enough. That is one of the reasons I did this book.

"I will argue till the cows come home and we all praise managers, but the people that helped me most were my teammates. The stuff I learned mostly was from Stuart Pearce, Steve Bruce, [Gary Pallister]. When you are in battles with them, they are the people you respect."

Keane suggested he would not have enjoyed being a part of a modern game that features players freely expressing their views on social media networks, as he lamented the end of the culture in the game that ensured dressing-room secrets were not made public.

The former Manchester United captain says he learned more from teammates than managers such as Sir Alex Ferguson. Phil Cole Getty Images Sport

"There was an unwritten rule that what went on preseason or in a dressing room didn't come out and that has changed," he continued. "There are pictures of players in dressing rooms on Twitter. The game is changing. I don't wish I was part of dressing rooms now.

"I look back on my career and say we had some great days, but I don't miss the carry-on that's going on now among players."

Keane went on to express his hope that the book will give his supporters an insight into his life and resolve, as he hopes his career is remembered for the good moments as well as the high-profile fallouts he had with the likes of Republic of Ireland boss Mick McCarthy back in 2002 and his acrimonious split from United boss Sir Alex Ferguson in 2005.

"The book is a fair reflection of the situations I've had in the last few years, whether it be with players or managers," he added. "I've been pretty harsh with myself in a lot of those situations and the mistakes I've made.

"This wasn't me writing a book in the hope people like it. If people like it then fair enough, but it was a chance for me to put the record straight.

"I think the book is quite upbeat. There are some good stories, I've had some great days. People focus on the negatives, but it's not all about falling out with people. Over the course of my career, I didn't fall out with that many people.

"A lot of the stuff in this book is me defending myself from things that are untrue. A lot of good things have happened in my career. People look at all the negatives, [but I had] great days and the highlight for me will always be the players I played with."