It has been a summer of frustration at Old Trafford. After the early arrivals of Ander Herrera and Luke Shaw, it seemed there was about to be a much needed overhaul at United. But during the last two months, we have been forced to be patient as new boss Louis Van Gaal gave the current squad a chance to impress him. Whilst that is fair enough, it has become quite clear that the squad is still in dire need of reinforcements after an opening day loss to Swansea City at home.

Although the nine injuries didn’t help the cause, inexperience told, especially defensively. Whilst using the new 3-4-1-2 formation in the first half, which worked so successfully under Van Gaal on the tour of the USA, United looked lost. Phil Jones, Chris Smalling and Tyler Blackett looked in desperate need of some guidance as a lack of leadership and communication at the back told.

After that poor showing in the first half, Van Gaal reverted to a more traditional back four with Jones switching to right back and Ashley Young at left back. Now Young is not the most popular player at Old Trafford despite his impressive pre-season performances at wing-back but no one can blame him for looking out of his depth at left back, which is a completely different kettle of fish due to having less defensive cover behind him. Therefore, it came as no surprise that a deal for Sporting Lisbon and Argentina defender Marcos Rojo was sealed within four days of the defeat.

Born in La Plata in Argentina, Marcos Rojo was promoted to his local team Estudiantes La Plata’s first team in 2009 having joined the club when he was 10-years-old. After winning the Argentinian Premier League and the Copa Libertadores, it was inevitable that European clubs would come calling. Enter Spartak Moscow, who snapped him up in 2010, signing him up to a lucrative five-year deal. But following just eight appearances in Russia, Rojo seeked pastures new, leading to three Portuguese giants reportedly chasing his signature.

Sporting paid just €5million to take him to Lisbon in the summer of 2012. It was unusual as clubs in Portugal usually buy unknown South Americans, but Rojo was already capped by Argentina. Rojo would go on to be used as a centre back at Sporting and despite his poor disciplinary record rather than his good performances making the headlines during his first year at the club, he improved massively last season. After just surviving relegation in 2012/13, Sporting managed to finish in a surprise second place last year, with Rojo becoming one of their key players.

It is obvious that Van Gaal has been looking for specialists this summer, namely a left-footed central defender who can play at left-back. The snub of Thomas Vermaelen due to Arsenal’s demands of a swap deal told us that. Rojo was the next name on his list. In the 3-4-1-2 formation, which he is determined to make work; Rojo is likely to be used as the left centre-back. At Sporting, his positioning was sometimes questionable in a back four as he liked to maraud up the pitch. With more cover in a back three, he will have more freedom to start attacks as well as doing his obvious defensive duties.

But in the summer, we saw a different side to Rojo. In the successful Argentina side which reached the final, we saw him play as a left-back in a back four to great effect. Rojo was solid throughout the tournament and proved that he has an engine and is a threat in both final thirds, scoring the winner in Argentina’s 3-2 win over Nigeria in the group stages. His versatility will be a crucial reason to why Van Gaal identified him as a target. The Dutchman likes his players to be capable of playing in several positions within his system. Rojo will provide United with cover at left centre-back, left wing-back and at left-back should the manager revert to four at the back again, meaning Young won’t be used in that role again.

United need a presence in their back three and the new number five can offer that, even if he can be hot-headed. Rojo will always give 100% to his sides’ cause but he comes to Old Trafford with 21 yellow cards and four red cards from his 49 appearances at Sporting. Added to that, he got himself suspended for the World Cup quarter-final win over Belgium in the summer. Van Gaal will be hoping to use the aggression he has in a positive way, taming the animal inside Rojo will be key to whether he will be a success at the club. There is no doubt the 63-year-old won’t stand for any bulls**t from the new Argentine.

On a more positive note, Rojo has excellent physique. He is very strong in the tackle, extremely quick and good in the air. His speed will help him recover should he not improve on his positioning. The 24-year-old also has excellent passing ability, which will be a major factor in why Van Gaal was attracted to him as he likes his defenders to be reliable in possession. Rojo would appear to have all the attributes to turn himself into a top defender and in Van Gaal he is now working under the right coach to improve his game and reach his potential.

Whilst that potential is there, United fans will just be happy that a central defensive reinforcement has come into the club, as it was getting pretty desperate. Rojo has a lot to prove upon arrival and with that number five shirt comes pressure, after Rio Ferdinand’s fruitful 12 years at the club. The Argentine has to hit the ground running by helping United win some games and keep some clean sheets. No pressure, Marcos.