Early morning in the Chicago sunshine and captain Bruno Fernandes is helping Luke Shaw and Matheus Cunha adjust their GPS vests before Manchester United train at Soldier Field.

It’s an inconspicuous device that sits between the shoulder blades, but the myriad of information it transmits to United’s analysts and sports science team can make a huge difference in the never-ending crusade to get the best out of the players and prevent injury.

Not a single piece of data is wasted. No stone left unturned. As Ruben Amorim explained on United’s summer tour of the US, there is no hiding place for his stars when the science provides irrefutable evidence.

‘If you don’t train in the right way, I have footage to show you. And I show you in front of everybody. I’m always on top. In the moment, if you train one time badly I will show you the image. I will not just speak with you, I will show everything.’

Sports science has moved on significantly from the days when Bolton manager Sam Allardyce allowed Ian Marshall to train at home in Leicester using a club-issue heart monitor, and was impressed by the results until it transpired the veteran striker had been putting it on his dog Tess.

Manchester United have been using GPS vests during pre-season training to track key data

It’s an inconspicuous tracking device that sits between the shoulder blades within the shirt

Bruno Fernandes could be helping Luke Shaw and Matheus Cunha adjust their vests prior to training in Chicago 

It is well known that Erik ten Hag sent the United players on a punishment run the day after they lost 4-0 at Brentford three years ago because the data showed that they had lagged behind their opponents by a total of 13.8 kilometres.

That was only August 2022 but the science has advanced into a whole new realm after United renewed their sponsorship deal with STATSports to wear the upgraded 2.0 version of the Apex GPS performance trackers.

The state-of-the-art technology will enable the club’s analysts to monitor the players in action more accurately, saving coaching staff an estimated 20 hours a week which can now be spent on deeper analysis.

Ed Leng, head of physical performance at United, explained: ‘At Manchester United, we’re always looking to push the boundaries of player performance and wearable trackers are a vital part of that process.

‘The Apex 2.0 trackers will enable us to unlock deeper insights across all men’s and women’s players spanning all training environments, from academy to first team. Real-time tracking capabilities help us to better prepare, develop, and protect our players.’

As part of the agreement, six beacons the size of iPads will be installed at Old Trafford, two at each end of the ground. Up to eight more will be in use at Carrington to cover six pitches.

Portable beacons can also be attached to tripods for use at away games or remote training bases, as they were on this summer’s US tour.

The GPS units slot into pockets on the back of the players’ vests and transmit their individual data to the beacons which send them to the sports science staff.

Erik ten Hag handed United players a punishment run the day after they lost 4-0 at Brentford when he was manager in 2022

The Apex GPS 2.0 performance trackers by STATSports provide United’s staff with 300 different metrics per 90-minute training session

The data is transmitted to Man United’s staff in an instant so they can analyse the findings 

The new system uses real-time kinematics, providing pin-point accuracy to the neatest millimetre in terms of positioning and navigation, so a player’s every movement and reaction is logged and shared in an instant.

The Apex has roughly five-million data points per 90-minute training session, give or take, which provide United’s staff with 300 different metrics.

These are separated into internal metrics, such as a player’s heartbeat, and external which includes categories like distance covered. This can then be broken down even further into accelerations, decelerations and high-speed runs to work out the dynamic stress load on each player.

‘You think of the likes of Kobbie Mainoo pressing and then having to make a hard run back,’ explains STATSports managing director Paul McKernan. ‘We break the categories down, first of all internal and external, and then you look at the distance and volume metrics as well.

‘We provide 100 per cent accurate live data and we are the only people in the industry worldwide who have that.

‘Why’s that important? Because when you’re standing by the side of the training pitch, you can make decisions on the players based on data you see in front of you, not waiting until after the session and downloading the data and saying, “I wish Mason Mount had run a little bit further or done a few more sprints, or actually he did too much today”. You need to make that decision in real time and that’s based on the accuracy of the live data.

‘As technology evolves, we are able offer that next level of accuracy in terms of the speed we can operate at, the speed we can download the data, and how quickly we can transfer it to the beacons and back to the iPad. It’s bringing the accuracy to a whole new level compared to what it was previously.’

One major benefit is that the sports science staff can spot when a player is entering the ‘red zone’ and prevent him sustaining an injury by pushing too hard.

Ruben Amorim wants his players to run more and have higher fitness levels this season

Rivals Liverpool also use STATSports and their fitness levels drove them to Premier League success last season

‘In pre-season, they will be monitoring the players to build up to where the sports scientists know where they can reach in terms of distance covered, match speeds, the metres of high-speed running, but they want to do that in a safe way to make sure they don’t get injured,’ adds McKernan.

‘They can do that from understanding the history and years of data that they’ve got on each player that we’ve been able to provide them with.

‘That’s one aspect of it. The other is that in real time they can look at the dynamic stress load. It’s a predictor of injury. We can predict when players are moving into that zone.

‘Making that decision in real time is so much easier when you have accurate data in front of you versus waiting until someone strains a hamstring, and you look at the data afterwards and say “if only we had known”.

‘Our software all works around the match day. We tailor situations for match day minus two and minus one, in terms of the load we would put on a player.

‘The biggest thing for any sports organisation is to have all their players available. We help with availability to play and at the least risk of injury as possible – and they are ready to play at the optimum time.’

STATSports work with nine other Premier League clubs – Liverpool, Manchester City, Arsenal, Tottenham, Everton, Brentford, Crystal Palace, Wolves and Burnley – and have seconded a member of their staff to work with United full-time so the technology can be best tailored to their needs.

‘Manchester United are looking to push the boundaries of performance, and as a key partner we want to help them with that in any way we can,’ says McKernan.

‘Liverpool had a great season obviously, but keeping the players fit was a big part of it. We can provide the same data, it’s then how they use that. The guys have done a great job at United before in terms of trying to move it on, and hopefully they are able to take another step within that.’