Manchester United's summer transfer window fell short of the expectations many had.

After securing Champions League football and finishing the season strongly under Michael Carrick, United made only four signings, including backup goalkeeper Karl Darlow.

United prioritised the midfield, but they were forced to pivot in their plans after missing out on several top targets, including Elliot Anderson, Mateus Fernandes and Sandro Tonali.

In the end, United signed Andrey Santos, Youri Tielemans and Carlos Baleba. All those players are very good in their own right, although there is an argument to be made that there were other options on the market better suited to what Carrick needed.

United decided not to sign a defender. They held talks about signing a left-back, and Lewis Hall was a top target. However, they seemingly did not consider the prospect of signing a new central defender, despite a major lack of quality in that position.

One of United's biggest errors in the summer was not selling Lisandro Martinez. The decision to keep the Argentine defender at the club is somewhat incomprehensible when you look at the full picture.

Martinez's deal expires in the summer, and United have the option to extend for a further year. His contract situation at the time would therefore have given United solid leverage in negotiations to extract a sizeable fee. He had also just enjoyed a good World Cup campaign and his stock was fairly high.

He has also had several long-term injuries during his time at Old Trafford and has proven that he is, from a fitness perspective, not reliable.

Another reason is the way United went about their midfield rebuild. Baleba is an elite athlete, but none of Santos, Tielemans and Mainoo is. The lack of athleticism and mobility in United's midfield means the club need athletic centre-backs to make up for that.

Martinez is an excellent ball player, but out of possession, he is a liability. He is not the quickest, is poor at defending the wide areas and big spaces and also poses little to no aerial threat. 

Martinez has been very poor so far this season. He has cost United several points already, and the lack of maturity he displayed against Chelsea was unacceptable for a player of his experience. However, Jason Wilcox and Omar Berrada also have to take the blame for not selling a player when it was obvious it was the perfect time to part ways.

By selling Martinez, it could have gone a long way in helping United fund the signing of a new central defender who is better suited to what the squad needed.

INEOS are continuing to prove that they are not proactive. Instead of selling Martinez in the summer, which would have been beneficial for all the reasons mentioned above, they failed to do so and now risk losing the defender for a minimal fee, or even on a free transfer next summer.

Recent reports now claim the club is exploring a deal to sign Dominic Calvert-Lewin in January, even though it was clear in the summer that Carrick needed another option in the striker position for squad depth. Again, the club have waited too long. 

Manchester United claimed they were restricted by financial regulations in their summer spending, but if the club has the money to sign a striker in January, it means they had the money to sign one in the summer. 

Additionally, United spent over £60 million on land for the new stadium. That money could’ve also been used to strengthen the squad.

The money was there. The Old Trafford hierarchy simply took the active decision to not pursue further signings, which points towards a lack of sporting ambition.