The saga that is Manchester United's midfield rebuild took yet another twist over the last 48 hours.

A week ago, everyone expected Ederson to be the first player signed to kick-start the new-look engine room at Old Trafford. As we know now, that's no longer the case.

Instead, Andrey Santos became the first official arrival of the Michael Carrick era. That same day, an unforeseen deal for Aston Villa's Youri Tielemans emerged, and the Belgium captain looks set to join.

The duo will link up with Bruno Fernandes, Kobbie Mainoo and Mason Mount in shaping how Carrick sets up his midfield this season. It's an interesting group to say the least, but the speculation has always been that United wanted three new midfielders this summer. If they want the perfect balance, they still need one more. The question becomes: what do their current options offer and what do they need to complement that?

What does United's midfield currently offer?

United fans are already well aware of what Fernandes and Mainoo bring to the table. The former is a creative genius, the latter a composed link player. His range of passing might not be the most extensive, but his decision-making in possession allows him to be the deep-lying bridge between defence and attack.

Mount has never truly found his place at Old Trafford, minus a brief resurgence under Ruben Amorim. However, fans know he's a hard worker off the ball who can trigger the press either from deep or further forward, while offering a goal threat if utilised in the right positions.

What about the new boys? Part of why the Tielemans move was so surprising was that it was a departure from what it seemed United were looking for. The focus with Ederson and Santos appeared to be a more traditional No 6 to replace Casemiro in a defensive sense.

Though he was mainly used as a substitute, Santos ranked in the top four last season for duel success across Premier League midfielders and in the top 25 for tackles and interceptions per 90. Ederson ranked in the top 40 across these categories in Serie A. It's nothing outstanding, but combined the pair may have been trusted to have enough between them.

Tielemans appears more of a pivot from that. The Belgian is a more creative version of Casemiro. They tended to operate in similar areas, yet Tielemans was the best at playing line-breaking passes last season in the entire English top flight. Better than Fernandes. Better than Casemiro.

He can defend too. 2.8 tackles per 90 is better than Santos, though he averaged less than one interception. In that sense, he and Santos blend together well. He can also take some of the workload off Fernandes and Mainoo offensively.

That makes it seem like everything is coming together rather nicely. Yet, there remains one glaring area the United midfield lack. Legs.

In terms of distance run per 90 last season (of players who played 1000 minutes or more), United's best performer was Mainoo (11.9km). That put him 26th among Premier League midfielders. Santos (11.5km) ranked 52nd, Fernandes (11.3km) 68th and Tielemans (11.1km) 77th.

Admittedly, they are all better than Casemiro, proving that it isn't about running around like a headless chicken. Having elite positional awareness is just as important. But very few possess that like the Brazilian. So, the alternative is to find someone with enough legs to make up for it.

Who can be United's midfield runner?

Some of the names United have been linked with include Alex Scott of Bournemouth, Joao Gomes of Wolves and Carlos Baleba of Brighton. Despite on the surface appearing to be more mobile options, the latter two were actually worse than Tielemans last season when it comes to distance ran.

They both have their strengths defensively despite their lack of running. Of the midfielders who played 1000 Premier League minutes last season, Gomes ranked seventh per 90 in tackles and Baleba eighth in interceptions. Gomes also ranked third in possessions won in the defensive third, which is probably where he will need to spend most of his time.

In terms of his running, Scott ranked 42nd of Premier League midfielders. An improvement on the others and equal to the second best United had to offer. That doesn't necessarily translate to elite stats elsewhere though.

While he ranks an impressive seventh in possessions won, he drops off in tackles (49th) and interceptions (29th). He does create more chances than Gomes and Baleba, but with Fernandes and Tielemans especially, it feels like United don't need to overly focus on this area.

If you look purely at the running stats, the likes of Brighton's Jack Hinshelwood and Yasin Ayari could make compelling cases. They are both far more active than Baleba at the Amex, but in the case of Hinshelwood, his running doesn't lead to much in the way of other data that can appeal to United.

Ayari might (23rd in interceptions, 38th in tackles), but would United rather opt for someone who covers less distance but performs slightly better?

Manu Kone and Ayoub Bouaddi are others that have been linked previously, while there is always the chance that Ederson is revisited at a lower price. Yet, they still aren't quite as complete as the biggest outlier.

James Garner's name consistently appears high in categories it seems as though United need to improve on. While his running stats may be nothing to shout about, no player covered more total distance in the Premier League last season.

He also features in the top 10 for both tackles and interceptions per 90. He is also a top performer in possessions won in the defensive third (16th).

The once United academy star has come on leaps and bounds since leaving Old Trafford and now offers an interesting alternative as the final missing piece of the midfield puzzle. It wouldn't be the most glamorous move, but a lot of the data points towards him being the best paper to cover the remaining cracks in Carrick's midfield.