Andre Schurrle and Willian have further strengthened the attack, while Marco van Ginkel has been brought in as the eventual replacement for Frank Lampard and Kevin de Bruyne has returned to the club after a season on loan at Werder Bremen.
With only three recognised strikers in the squad, many have questioned why Mourinho wanted to spend £32 million on Willian. Jokes about getting one over on Tottenham Hotspur aside, there is method in the supposed madness of stacking the midfield with talent.
Strength in depth was something that was sorely lacking at Chelsea last season.
They relied heavily on the Three Amigos of Eden Hazard, Juan Mata and Oscar, leading to extreme fatigue by the end of the season. The trio were involved in a total of 194 games for the club, with no comparable talents to afford them a much needed rest. This will not be the case this year, as the summer signings offer a far better backup than the likes of Yossi Benayoun.
Mourinho has spent 16 years honing his craft and perfecting his system across Europe’s top leagues. The key element of any of his teams is the ability to swiftly transition from defence to attack, with the midfield expected to contribute at both ends of the pitch.
The players he has surrounded himself with at Chelsea will start in a fluid 4-2-3-1 formation, adjusting to a more straightforward 4-3-3 when necessary.
In a 4-2-3-1, Frank Lampard and Ramires will alternate in the box-to-box role, while van Ginkel or John Obi Mikel shield the back four. If a 4-3-3 is preferred, Ramires would move out to the right, with Hazard likely dropping back to the left of either defensive midfielder.
Hazard has already reaped the benefits of playing in the Mourinho system as he continues to develop his game. Deployed on the left of the attacking trio this season, he has done more defensive work than he did throughout 2012-13 as Mourinho looks to turn him into an all-round superstar.
Oscar has shown his ability to drop deeper to pick up the ball, and his skill at linking the transitions will prove key to Chelsea’s success. His defensive contribution in 2012-13 was higher than Hazard and Mata combined, and the blistering start he has made to the season so far bodes well for his future within the Mourinho setup.
Mourinho has expressed a preference for Mata to cut inside from the right wing, and Willian will do the same from the left. They will still be expected to contribute defensively, but their overall role will be to support the striker in attack.
Schurrle offers versatility as he can play anywhere up front. He plays as a centre-forward for the German national team, and although he was ineffective in this position against Manchester United, he provides excellent emergency cover for the three strikers. However, it is likely that he will spend much of the season as part of the midfield trio, featuring heavily in the cup competitions especially.
It may seem as though Chelsea are overloaded in the middle of the park, but the reality is that Mourinho has built a squad with the talent and skill necessary to play the quick transitioning, counter-attacking football that has become his trademark.
A count of the trophies his tactics have won over the years suggests that those questioning his judgement should wait until the end of the season to measure the balance of his squad.