In securing the future of Vinicius Junior for another six years, Real Madrid have once again underlined their position of power in the transfer market.But as the structural issues of past campaigns loom — having finished eight points behind Barcelona in La Liga last season to make it two seasons in a row without winning a major trophy — have they done so at the cost of tactical cohesion and balance?There can be little doubt about the ability across Madrid’s front line, with the devastating pace and finishing ability of Kylian Mbappe complementing the relentless creativity and flair of Vinicius Jr out wide.The addition of exciting young winger Yan Diomande in a deal worth up to €140million ($162m; £120m) only adds to their unrivalled firepower — a squad that, on paper, has the potential to blow most teams in La Liga away on individual quality alone.But Madrid’s issues have never been about scoring goals. And while the prospect of Vinicius Jr linking up with Mbappe, Diomande and buccaneering new full-backs Marc Cucurella and Denzel Dumfries on the opposite flank remains mouthwatering, his new contract does little to address the top-heavy nature of the squad, making it difficult for managers to formulate a solid plan when the team do not have the ball.Vinicius Junior in Real Madrid training after his renewal on Friday (Victor Carretero/Real Madrid via Getty Images)All of Carlo Ancelotti, Xabi Alonso and Alvaro Arbeloa opted for a 4-4-2 out-of-possession shape, leaving both Vinicius Jr and Mbappe up the pitch so they were well-positioned for counter-attacks.But both lack the defensive awareness to sufficiently protect the midfield, often making it easy for the opposition to play through that first line of pressure.Across 1,483 players who played at least 900 minutes in Europe’s top five leagues last season, Mbappe ranks 1,479th for tackles completed per game, while he and Vinicius Jr mustered two interceptions each all campaign. They rarely stopped opposition passes into midfield.Here is an example from early in Mbappe’s first season at the Bernabeu, with Ancelotti on the sidelines.Although their attacking talent eventually told in a 3-0 win against Real Valladolid, who finished rock-bottom and 25 points from safety, their opponents were able to find an easy route through midfield with movement inside from a full-back and pass-and-move football.As we can see below, Mbappe fails to cut the passing lane into Lucas Rosa, forcing Federico Valverde to push on. Rosa plays the pass inside to Mario Martin, who is not tracked by Vinicius Jr, opening up a simple one-two for the Valladolid players to get around Valverde and away.Such passages of play place strain on Madrid’s midfield four, particularly the two central midfielders, who constantly need to decide whether to push on or drop to protect the defence. High-quality opposition can exploit those moments of hesitation by getting dangerous technical players into the spaces they leave behind.Another byproduct of keeping Vinicius Jr and Mbappe in the side is that it forces one (or both) of Valverde and Jude Bellingham to defend the flanks, taking them away from their preferred positions in the middle.Bellingham scored 19 La Liga goals in his debut season and was able to make late runs into the box from his central midfield position. His excellent performances for England at the World Cup this summer, meanwhile, only highlighted his potential from an advanced role.But his athleticism and versatility also means he is the most likely to be given a covering role, offering the best defensive protection alongside the similarly dominant Valverde down the flanks.It nullifies Bellingham’s attacking output, and leaves him defending large spaces without the ball, meaning teams can still play around him in much the same way as Valverde in the example above.Here is an example of the stretched 4-4-2 shape almost two years later against Barcelona, where Arbeloa’s Madrid struggled to contain their swirling movement in midfield.Even without the injured Mbappe, Madrid attempt to step up in their defensive shape with Gonzalo Garcia pressing from the front. But the quality of Barcelona’s players in the build up means they are able to side-step the pressure and find Pedri in a pocket of space.It is an example that highlights the stress on midfield — Aurelien Tchouameni hesitates to follow the press with Ferran Torres lurking behind him. He is pointing at Pedri as the pass comes in, but probably should have been the player to close the midfielder down himself. With so much space to cover, pushed and pulled by the opposition’s possession, lapses in concentration and communication naturally arise.All the while, Bellingham is left covering the flank. He completed just 18 passes — his fewest all season — and took zero shots on goal. It can leave the Englishman on the periphery, but bring him inside and Madrid are exposed down the sides.Without any signs of real restructuring in the transfer window, it leaves a lot of pressure on incoming manager Jose Mourinho to find a solution.Some of the summer arrivals will help. Bernardo Silva brings more energy to midfield, and is tactically intelligent enough — having worked under Pep Guardiola for nine years at Manchester City — to cover the correct spaces and plug the gaps when Madrid do not have the ball. Cucurella also brings defensive tenacity down the left, and may help to ease the burden on the left-sided midfielder in the 4-4-2 formation.Diomande arrives with the ability to play on both sides and is a more defensively-engaged option, having thrived out wide in the intense system of RB Leipzig and the Bundesliga. But, given Madrid’s plentiful options on the left, the 19-year-old likely arrives as the first-choice winger on the right, where he may be asked to defend the flank in the 4-4-2 ahead of Trent Alexander-Anrold or Dumfries, a potentially risky move in bigger games.Madrid still managed to rack up an impressive 86 points last season, winning nine and drawing one of their 10 home games against bottom-half teams. They are, and will continue to be, an intimidating prospect at the Bernabeu under Mourinho, who will be able to unleash his attacking ammunition against weaker sides.But since the arrival of Mbappe, they have failed to reach the heights of 2023-24, when Bellingham was able to crash the penalty area from his central role and the team were more solid without the ball. That has been made difficult with two defensively negligent players leading the line rather than one.Significantly, they have lost six of their seven meetings with Barcelona in that time, and conceded 22 goals to their fierce rivals.There are pieces that Mourinho can move, but Vinicius Jr’s extension feels like a missed opportunity to rebalance the team — and address the real issues behind their struggles to reclaim La Liga and seriously compete in Europe once again.