Roy Keane reveals the huge signing on bonus he was paid by Man United back in 2003

It's double what Gary Neville was offered

This week's episode of popular podcast The Overlap took an unexpected step as Irish footballing legend Roy Keane brought out a few of his old Manchester United contracts.

After the 54-year-old ex-Manchester United legend had successfully dusted off the old papers, he and former teammate Gary Neville got to reading them over in detail.

The contracts shine a fascinating light on some of the lesser known details that go into the negotiations between players and clubs when it comes to agreeing terms.

One clause, that can be seen on camera, shows a promise by United to provide flights to Keane and his family so he could travel between Manchester and Cork in Ireland.

It reads: "The club will provide 20 return flights Manchester/Cork/Manchester for the use of the player, his partner and children for each year of this contract commencing from 1 July 2002."

Another shows the legal agreements clubs must provide to allow players to leave and play international football during the season.

The clause reads: "The club shall release the player for National Representative matches for which he is selected in accordance with the principles of co-operation between Member Associations of Fifa and their clubs."

The contract also revealed the mouth-watering amounts of money Keane was being paid almost 30 years ago.

Reading out the details, Neville said: “You signed a contract in 2000 for £950,000 per year, which is £20,000 a week.”

Keane responded: “Does that include signing-on fee, Nev?"

Neville said: “Just basic wage… then you’ve got the contract that was signed in 2003. Then there’s a contract for £2.75m a year from 2000 to 2003.”

The Irishman's signing-on fee was split across a four-year contract, which would see him be paid £1 million every year until it expired, bringing up his overall annual income to £3.75 million.

Both Neville and Keane played over 400 games for the Red Devils during the club's period of unprecedented success in the early 2000s.

However, despite their similar respective roles, Keane's contract showed a clear discrepancy between the wages each player was earning.

Neville told the podcast: "That’s double what I was earning in my last contract [in 2011]”

At this point Jamie Carragher interrupted to say: “Yeah, but he was three times the player,”

Gary Neville responded: "He [Keane] left seven years before me, I finished on £2.3m in 2011,”

“I didn’t negotiate my contracts; I just signed them. I wasn’t bothered.”