As Sergio Aguero scored his third goal at Stamford Bridge, the TV cameras focussed on a pensive Roman Abramovich, his inscrutable expression revealing so little and yet so much. One wondered if he felt the same sense of detachment that a growing number of Chelsea fans have confessed to feeling this season – something beyond sadness or anger, an emotion bordering dangerously close to apathy. It is hard to escape the feeling that this Chelsea team, champions of England though most of them may be, are less invested in the club and its fans than the previous title-winning sides that the present generation grew up with.

1. John Stones (Everton)

In an age when players are extolled and maligned in the same breath, it is easy to lose sight of the fact that, in terms of a senior football career, John Stones is barely four years old. There are several aspects of his game that undoubtedly need improvement – his defensive positioning in particular –but Stones has been the victim of his own reputation to a great extent this campaign. The 21-year-old’s strong technical grounding is a solid foundation for a manager like Antonio Conte to build upon. Chelsea’s need for a ball-playing centre-back has been glaringly obvious for a while now, with the Blues never truly filling the Ricardo Carvalho shaped hole in their backline. Stones could be the answer.

Sceptical Blues supporters need only cast their minds back to Kurt Zouma’s first appearances in a Chelsea shirt and his subsequent progress under the tutelage of Jose Mourinho, John Terry and Gary Cahill. Stones would likely develop into as much if not a more solid defender playing alongside teammates and managers with experience at the highest level of the game. His athleticism and mobility also make him suited to one of the wider centre-back roles in a back three, a big advantage should Conte decide to use his favoured 3-5-2 formation at Stamford Bridge.

2. Kostas Manolas (AS Roma)

A more experienced and potentially cheaper alternative to John Stones is Roma’s Greek centre-half Kostas Manolas. Although the 24-year-old is shy of being world class, he is the definition of the type of defender Chelsea need at present – agile, quick and supremely comfortable on the ball. Manolas’ defensive attributes are more than good enough to earn him a place in the Chelsea first team, but like with Stones, it is his quality on the ball that makes him such an attractive option.

One of Manolas’ biggest strengths is his ability to stride forward with the ball after escaping the first line of opposition pressure. The Greece international is also known to attempt marauding runs in the opposition half on occasion – an assist against Udinese this season coming from one such foray into the attacking third. His presence in the Chelsea defence would allow Fabregas to take up positions in more central areas of the pitch, while allowing the Blues to move the ball faster – crucial for the link-up play between Fabregas and striker Diego Costa.

At 6ft 2in, Manolas has a no-nonsense swagger about him that would – despite agent Mino Raiola’s suggestions to the contrary – make him an ideal fit for a top Premier League side. His athleticism suggests that he would fit in seamlessly in a 3-5-2 system if Antonio Conte were to use that at Chelsea next season. Additional protection from fellow central defenders could also give him the freedom to stride forward more frequently with the ball.

If you were to give the average Chelsea fan a piece of paper and ask him/her to write down what the team has been lacking this season, you would likely get a fairly good description of the force of nature that is Radja Nainggolan. Drive, leadership, tenacity, fight. The Belgian midfielder has those qualities and more in abundance, but most importantly, fills a need in a footballing sense in the Chelsea midfield.

Particularly since the departure of Ramires, the Blues have lacked the presence of a true box-to-box midfielder in their squad. Any combination in the midfield pivot for Chelsea lacks pace, and the shortcomings of Jose Mourinho’s preferred Matic-Fabregas midfield have been exposed multiple times over the course of the past year. Although Nainggolan is not lightning quick by any means, the Roma midfielder is certainly more dynamic than John Obi Mikel, Nemanja Matic and Cesc Fabregas. A player with sound technique, his true value lies in the fact that Antonio Conte can rebuild a broken Chelsea squad with the Belgian at its very centre.

4. N’golo Kante (Leicester City)

Chelsea’s manifest need for a box-to-box powerhouse was perhaps best highlighted in the 1-1 draw against Stoke City at the beginning of March this season. The juxtaposition of a rampaging Gianelli Imbula – a player the Blues had been linked with in the summer – with a static Nemanja Matic and John Obi Mikel was indicative of the fact that Chelsea needed to address their midfield problem on a priority basis in the summer transfer market.

The industry of Kante will be crucial in order to provide protection for Fabregas in midfield and the France international would also form a formidable partnership with Nemanja Matic, with the Serbian showing this season that he is more of a box-to-box player than a pure defensive midfielder.

Another big plus is that Kante is still only 24 years old and has room to grow. What remains to be seen is whether he is willing to sacrifice a season of Champions League football to move to Stamford Bridge in the summer.

Chelsea’s need for a second top-quality striker has been painfully obvious this season, with Diego Costa taking half a season to get going and the likes of Loic Remy and Radamel Falcao struggling with form and fitness. Even at the best of times, Costa’s propensity for picking up suspensions and his hamstring issues mean that the Blues need a reliable striker to provide the Brazil-born Spain international with serious competition.

Higuain has had a stunning season with Napoli in 2015-16, scoring 32 goals in all competitions, including 30 in the Serie A. The Argentine is primarily a poacher, but the most noteworthy aspect of his performances this season has been his link up play with team-mates Lorenzo Insigne and Marek Hamsik among others, as well as his ability to shoot accurately from around the edge of the penalty area. The former Real Madrid man is a different type of player to what Chelsea currently have in their squad, and although he has gained notoriety for some glaring misses in the biggest of games, the Blues would be helped with a consistent goalscorer like him.

Chelsea face a pivotal summer transfer window, with their task made all the more difficult by the team’s failure to qualify for next season’s Champions League. The appointment of Antonio Conte is a positive first step on the road to recovery, but Roman Abramovich and the board must back it up with a successful transfer window to ensure that the Blues compete for the highest honours once again and soon.