The World Cup is not only football's biggest tournament, but it also serves as a shop window for players to impress onlooking clubs.
Jose Mourinho's first season back at Chelsea ended in disappointment as the Blues failed to land a trophy, but fans can be confident that they will mount a title challenge next season having come so close this time around. Mourinho will now be planning a summer of spending in order to get Chelsea over the finish line, and some World Cup stars may be of interest.
With central midfielders and strikers needed at Stamford Bridge, you can be sure that Mourinho will be bringing some new faces in to fill those holes, whilst depth could also be added to the defence. With that in mind, here are five stars playing in Group F at this summer's World Cup that could fit the bill.
Ezequiel Garay, Argentina
With David Luiz heading to Paris Saint-Germain and John Terry's career coming to an end in the near future, it's time for Chelsea to look for another centre back. They may have to move quickly as Bayern Munich are looking to sign him, but Benfica's Garay has been superb for the Portuguese giants since his 2011 switch from Real Madrid, and would be an excellent acquisition for the Blues.
Enzo Perez, Argentina
Finding a partner for Nemanja Matic in central midfield has to be a priority for Mourinho too, especially with Frank Lampard's departure from Stamford Bridge now confirmed. Perez, another Benfica star, was actually Matic's partner in the first half of the season and the duo could reunite their partnership in the heart of the Blues midfield should Perez impress at the World Cup this summer.
Ezequiel Lavezzi, Argentina
Despite already having the likes of Eden Hazard, Willian, Oscar, Andre Schurrle and Mohamed Salah at his disposal, Mourinho has been repeatedly linked with a move to sign PSG forward Lavezzi. The former Napoli man impressed against the Blues in the Champions League and possesses plenty of speed and an eye for goal - something the Chelsea frontline has lacked over the past two seasons.
Senad Lulic, Bosnia
A versatile player who can play anywhere down the left hand side, Lazio's Lulic is one of the more well known players in the Bosnia squad for this summer's tournament. A hard working player who possess quality in possession, Lulic has established himself as one of the key players in Lazio's side since his 2011 move from Swiss side Young Boys, and he's already attracted interest from Chelsea.
Miralem Pjanic, Bosnia
If Mourinho wants to sign a central midfielder who can get forward, score goals and create chances to replace Lampard, then Roma star Pjanic should be on his radar. The 24-year-old hit six goals and six assists for the Serie A side this season, and Manchester United were reportedly watching the £25m-rated playmaker. Alongside Matic, Pjanic would certainly improve Chelsea's midfield.