Michael Carrick’s game in the Premier League wasn’t what anyone could have hoped for – and that goes for the boys’ eyes too but Casemiro, at 34, has yet to demonstrate all his worth with Manchester United. When the Brazilian was left out of the squad, United’s midfield lacked the depth, leadership and control that was a worry at the turn of the season.

Carrick said that Casemiro will be back for next week’s match against Nottingham Forest, but the Sunderland game was a stark reminder of how tough it’ll be to replace him for Manchester United this summer. Numbers speak thundersounds. It’s been seven times this season that United has recorded a league loss without Casemiro in the lift-off, and what they did in the recent clash at the Stadium of Light was the final nail in their coffin.

The first is that starting from the first whistle, United had no authority in the midfield. Sunderland dominated the play for much of the match, made better chances and were much more settled in the transitions. But with Casemiro and Manuel Ugarte both absent, Carrick had to make some changes to his midfield. The part of seven had become more Kobbie than ever while no wonder Mason Mount played further forward and touched down with Bruno Fernandes.

The balance just wasn’t present, though. Mainoo had certainly not been the ideal choice for the ‘settler’ in the attacking role, and has also demonstrated he is inexperienced in the deep-lying role, with United now rather raw.There’s no denying his party was rather raw, but it’s also a conversation point that Mainoo has never been the logical deep-lying option, particularly when attacking Sunderland were fresh. The main difficulty for United was the ability to move the ball together through midfield and Sunderland managed to get on the edge of it with the ball on several occasions.

The headline figure of concern was made in attacking. Manchester United were unable to score through until the dying embers of the final minute in which Matheus Cunha was the final man to test Sunderland’s lastgen stoppage time goalkeeper Robin Roefs. The loss of any creativity and control was alarming for a team looking for Champions League consistency.

Carrick denied mental fatigue had set in to his players, after the game, when it was suggested that the squad had spread their best performance already. The United coach had to acknowledge that the team was still as committed and as motivated as they can be, but even that could not be achieved without Casemiro at their centre of the park centre.

The Brazilian’s suitcase (or shoulder) isn’t limited to tackles and interceptions. His experience, positioning and game management continues to be vital to Manchester United. Elderly midfielder Sutherland Regis le Bris made an accurate comparison between Casemiro and the veterans of his time, Granit Xhaka, after the pair’s complementary performances, in this regard.

Le Bris noted that a master will also be able to handle situations under pressure, control the tempo of games and direct teammates through challenging situations. All those qualities don’t really show up in statistics, but when they’re gone, you see them. Casemiro, however, is still there to give the midfield a sense of leadership, tactical sense, and composure that they don’t always have on their own.

Manchester United’s recruitment drive this summer is indicative of that worry. Internal favourites include Nottingham Forest midfielder Elliot Anderson, who is seen as the club’s first choice to replace Hall, as well as Crystal Palace midfielder Adam Wharton, Brighton’s Carlos Baleba, West Ham’s Mateus Fernandes and Bournemouth’s Alex Scott.

But the Sunderland game made it clear, however, that the issue of youth at midfield wasn’t necessarily the remedy. Casemiro’s job is not only to be a tech guy, it’s a psychological one. He is responsible for setting up the midfield, covering his defence and trying to calm the meeting when games get heated. Those are attributes that do not come easily.

Limiting factors for Manuel Ugarte’s future at Old Trafford are also in question. The Uruguayan was thought to be the next in line to replace Casemiro, but there has been increasing uncertainty internally over his ability to enjoy a passing range and the same level of maturity to exert himself on the ball on a regular basis in the Premier League.

What that requires is that United will need a number of midfield signings instead of a marquee signing. A junior box-to-box regency could join with a defender-aside who can take up the challenge of the Premier League straight away.

In the interim Kobbie Mainoo’s development is a balancing game. The teenager has been most dangerous in the advanced roles where they are free to push and role-play in attacks. Lowering him in deeper unfortunately diminishes his attacking qualities as well as turns a lot of weight on a younger shoulder.

Lastly Manchester United is a lack of depth in their team. Carrick pulled five different players against Sunderland, but it was evident that quality is what has dropped. The key word for the event was lack of it – creativity, defensive protection and attacking threat were all absent from the team as a whole. It was a reminder of the fact that despite growth in the United ranks under Carrick, they are still further from a squad that they might consider to be fit and complete.

While he might no longer be as dominant in games as he was at Real Madrid, he’s still incredibly smart and an incredible leader for Manchester United. It’ll take skill, careful thinking and patience to replace that formula.

The Sunderland display was a warning for United, who may or may not be drawn toward signing some players in the free agency that’s expected during the summer. Finding the next Casemiro is not a case of just acquiring the talent, though this is of course important, but finding the control, experience and authority in the heart of midfield again.