Sam Allardyce is often seen as an old school coach who made football simple - but he was once known as one of the game's innovators who was open to new and different methods of management.

He took inspiration from American Football and utilised sports science many years before it became common. Those methods left a lasting impression on those who played for him and would themselves go on to become managers.

One of those was Wayne Rooney, with the former England and Manchester United captain revealing on his latest podcast episode how he was influenced by Allardyce in the latter stages of his playing career before taking his first steps in coaching.

"At the time I was under Sam [at Everton between 2017 and 2018] I was older and I knew I wanted to go into coaching," Rooney said on The Wayne Rooney Show.

"So I was more observing [Allardyce] as well and obviously as a manager you're looking at everything. But I was more observing and taking in what he was doing and how he was working."

A key influence in Allardyce's coaching style came when he played in America during the mid-1980s.

"A lot of the stuff came from NFL in America when I played at Tampa Bay Rowdies," he said.

"I went up looking at the NFL lads who were training pre-season, seeing the staff and everything. It had a massive effect on me.

"By the time I got to manage it was about experimenting and I did that at all the clubs in the lower divisions to get where I got. I used to test out something that was different."

One of Allardyce's most successful spells as a manager came at Bolton, who he was in charge of from 1999 until 2007.

During his early years at the club he introduced sports science, data analysis, nutrition plans and recovery methods - one of the first coaches to do so in English football.

"I wanted staff that said find me something that we can do that football doesn't do at the moment," he added.

"So we sectioned off every department and we gave the responsibility to the head of that department and they had to come and create their own their own way forward on what we're going to achieve and what we're going to do.

"This opened up their minds to saying can we get this piece of equipment in, can we go and visit this sport, why are we drinking this or why we're not drinking this type of electrolyte, why are we having food or why are we not having food at the end of the game? Where do proteins lie? What about ice baths? We had the first cryotherapy unit in the country."

Something both Allardyce and Rooney agree on is that in order to be successful there must be unity and a collective buy-in from both players and staff.

It is those on the football pitch who get the recognition but Allardyce and Rooney were both keen to ensure that those working behind the scenes were recognised for the work they did as well.

"When I was captain of England, at the end of one year I sent all the England staff to Las Vegas, I paid for them all to go out there," Rooney said.

"I paid for two pool parties for them all and stuff. Players doing things for the staff makes a massive difference."

Allardyce added: "We called it the team behind the team, the staff.

"We're all one team, but the team behind the team were the ones that supported them.

"It was a matter of generosity that the players would give to the staff at Christmas, because they weren't on great money."

For Allardyce, a role that was particularly important - and appreciated - was that of the player liaison officers.

"We had two player liaison officers, one male, one female," Allardyce said. "You can't imagine the part they played.

"They were the ones that sorted out the houses, the mortgages, the bank accounts. They were the ones that got the phone call, picked me up at the airport at midnight.

"They played a massive part. They sorted out Christmas parties for all the kids to come to and all that."

As well as building relationships with staff members, getting on with a club's owner is also important as a manager - something Allardyce feels is more difficult in the modern game.

"The trouble is now you don't speak to the owners, you speak to all of their employees at the football club," he said.

"[At Crystal Palace] when we got we got beat by Sunderland when we were both fighting relegation, [owner] Steve Parish came in shouting and screaming in my office, like me and Steve did, and I went, 'come on then, you're going to the dressing room, go on tell them how you feel' because he's a true Crystal Palace fan and owner.

"It was a cracking 20 minutes. I wish we could have recorded it."

Among the clubs Rooney managed include Birmingham City and Plymouth Argyle - both with owners who were based overseas - and he admitted not always being able to talk face-to-face was difficult.

He added: "The problem now is so many owners are abroad somewhere, you can speak to them over the phone but actually feeling that passion. Bill Kenwright was obviously chairman [at Everton] but it's the same, you see his passion for the club rightly or wrongly, and I think that's so important.

"Where I've had it with Simon Hallett at Plymouth, who lived abroad but he was very much a Plymouth fan and wanted to do the best, and then Tom Wagner at Birmingham. But to have that relationship, it's difficult over the phone."