In his very first press conference as United manager, Jose Mourinho declared that he would never use Rooney in a midfield role but the once world-class striker has already operated from a deeper position on a few occasions this season.
According to Souness, it was inevitable that the Special One would eventually leave Rooney out of his starting XI and he believes that there is no room for the England skipper in United's first-choice line-up.
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Rooney scored in United's first league game of the season at Bournemouth and is close to becoming the club's all-time top goalscorer, however his recent form has been poor and, at the age of 30, he is entering the final phase of his career.
Both Paul Scholes and Ryan Giggs thrived when they moved into deeper, more controlling central midfield roles towards the end of their respective careers. That said, Souness doesn't think that is something which Rooney can emulate.
He stated: "At first, I thought that Rooney would slip seamlessly into midfield, that he would drop in there and find it all a breeze, but he's been doing it for a year now and has found it really difficult.
"It's a different head you need in there. It's not enough to spread the ball out wide 40 yards, so the crowd say: 'What a pass'. It's about getting on the ball and sometimes that means standing still."
The Sky Sports pundit added: "He's such an honest, willing player, and always has been throughout his career, but he's not made that transition yet. It has not worked for him at all.
"I thought because of his attitude to the game and his ability, it would have, but it hasn't. If you don't get if after a year at 30, then you are never going to get it. He hasn't grasped the deeper-lying position and he isn't scoring or creating enough scoring opportunities to be the number ten."
With Juan Mata impressing in the number ten role, Souness rather surprisingly suggested that Rooney could find a place in the team on the wing but also pointed out the far more suitable options that Mourinho has in his squad for those positions.
"Out wide is maybe the only place that Rooney is going to get into Mourinho's team now, but he wants pace there and he gets that from Jesse Lingard, Marcus Rashford and Anthony Martial," claimed Souness.
Who should play in midfield?
The former Liverpool captain and manager also weighed in on the debate regarding Paul Pogba's ideal midfield partner and said that Michael Carrick should be the one to play alongside the world's most expensive signing.
"In centre midfield, Michael Carrick would be the best balance to Paul Pogba," the 63-year-old Scotsman said. "He sees the whole picture better than anybody else in there. The thing I really like about him is that he’s trying to go forward all the time with the ball.
"The first choice in there is trying to hurt someone right away, the second is going square and the third is going back. A lot of modern midfielders get away with murder and think they are doing a good job by simply keeping possession, going square and backwards.
"The priority has to be to get it forward to the people who need time on the ball — your strikers. Carrick is still the best at that. He maybe can’t play every game at 35, but he would be my man for the big ones."
Is Rooney good enough to play in midfield for Man Utd? Have YOUR say in the comments box below!