Chelsea will spend £50million in January, in order to bring in long-term target Eliaquim Mangala and Marseille midfielder Giannelli Imbula, according to the Metro.
The duo are thought to be desired by Jose Mourinho, who is looking to strengthen his squad at the next available opportunity, and could make the switch mid-season as Chelsea attempt to challenge for the Premier League.
Mangala, currently of Porto, has been heavily linked with a move to the Premier League for the last few months, with Manchester City and United also keen on the centre-back. However his release-clause, which is thought to be around £37million, has put most sides off of making a concrete offer.
Mourinho though is thought to be a keen follower of the 22-year-old, and is happy to meet the clause in order to add more steel to an unsteady back line. It is rumoured that the Stamford Bridge boss can lower the price to around £25million by using his contacts in Portugal, with Imbula thought to be available for the same amount.
The pair could cost up to £50million in total, but Mourinho may see it as an investment for the future with both players being under the age of 23.