Chelsea have continued their squad reinforcement and simultaneous stripping of Atletico Madrid’s resources by following up the transfer of Diego Costa with the purchase of Filipe Luis. Costa, who scored 36 goals for Atletico last season, was confirmed as a Chelsea player for a reported fee of £32 million earlier this week, before Atletico announced they had reached an agreement to sell Brazilian left-back Luis for a figure believed to be £20 million on Wednesday.

Luis will replace Ashley Cole, who completed his free-transfer to Roma this week, and is the latest purchase in a substantial summer recruitment drive by Jose Mourinho’s side. Teenage French defender Kurt Zouma will join up with the squad for the first time after signing from Saint-Etienne in January, Cesc Fabregas has been secured from Barcelona for £26 million, while young Croatian midfielder Mario Pasalic also arrived last week.

After fading away at the climax of last season to end up third in the Premier League and exit the Champions League in the semifinals, Chelsea will be desperate to finish Mourinho’s second season back at the club with at least one major trophy. And that should ensure that, despite already spending in excess of £75 million, more transfers will be on the way this summer.

With Samuel Eto’o’s contract having expired, Demba Ba close to finalizing a move to Turkish giants Besiktas and Mourinho far from convinced by either Fernando Torres or Romelu Lukaku, another striker is being sought in addition to Costa. The Brazilian-born Spain international expressed his desire to fight for a place with Torres, but Chelsea are thought keen to offload the Spain international, despite his £175,000 a week wages continue to be a stumbling block.

In addition to removing current players from the wage bill, the fact that Mourinho has always played with just one out-and-out striker could make signing another top-level option problematic. Edinson Cavani has long been cited as a target for Chelsea and Sky Sports reported this week that the Uruguay international had instructed his agent to look into a move to the Premier League.

Cavani was generally disappointing in the World Cup as he was against Chelsea in the Champions League quarterfinals for Paris Saint-Germain last season, and perhaps has suffered from being forced to play wide due to the presence of Zlatan Ibrahimovic. Certainly the 27-year-old has expressed his dissatisfaction with the situation. All of which makes it unlikely that Cavani will want to go to Chelsea where he could be in the same situation once again.

Another much-mooted option is Porto’s Jackson Martinez. The 27-year-old has been a prolific scorer with Porto over the last two seasons and scored two goals in his three appearances for Colombia at this summer’s World Cup. However, his €40 million (£32m) release clause has previously been a barrier to a move. Arsenal and Liverpool have also been strongly linked with a move this summer.

It may be that Chelsea instead turn to a club legend. Strong reports in recent days suggest that Mourinho wants to bring Didier Drogba back to Stamford Bridge as a back-up striker. The 36-year-old, who played for Chelsea for eight years and whose penalty won the Champions League with his last kick before departing in 2012, would also be handed coaching responsibilities. Mourinho will have to hope that Drogba’s emotional connection to the club proves decisive, with the free agent likely to have big-money offers from across clubs in the United States, China and Qatar.