Chelsea has done well in the transfer market this summer

Spanish international striker Diego Costa could prove a key signing for Chelsea next season

Chelsea boss Jose Mourinho like any other top boss knows his team’s weaknesses and has knack of finding the right players to strengthen his team.

This summer has saw the Blues sign a left-back, a central midfielder and a striker, all positions that the Blues were weak in after summer exits.

Exits

Mourinho has conducted his renovation of his Chelsea squad over two summers.

When he arrived at Stamford Bridge for his second stint at the club last summer there were calls for the Portuguese to get rid of the old guard.

The situation was the same with Andre Villas-Boas, who tried revolution rather than evolution and paid with his job. Mourinho has now allowed veterans Frank Lampard and Ashley Cole to leave the club, after their contracts expired.

Both have been stalwarts for the club, but it seemed the right time for the pair to depart. Maybe the best piece of business that the Blues conducted was the sale of mercurial centre-back David Luiz, who left the club for big spending PSG for a fee that could rise to £50million.

Luiz does have talent, but he also has a tendency to wander from his position leaving his defence exposed, as proven at the World Cup of course. The fee the Blues got for Luiz was a very good one.

The one questionable sale of the summer may be that of Romelu Lukaku. Chelsea got £28million for the highly-rated youngster, but with his potential I feel this deal could come back to haunt Mourinho in the next few seasons.

Mourinho has talked about question marks over the youngster’s attitude, but he is still young and already has a decent strike-rate in the Premier League. The Portuguese boss may well be proven right. However, I do think he will score goals for Everton next season.

Signings

Mourinho has made some shrewd signings this summer. With Ashley Cole departing Mourinho needed a new left-back, so he went shopping at Atletico Madrid and signed Brazilian international Felipe Luis, who was part of the best defence in La Liga last season.

Luis was unlucky to have missed out on the World Cup squad and helped Atleti claim the Spanish title last season also make it to the Champions League final. He may have been a cheap option compared to another believed target Luke Shaw, but he should turn out to be a very solid signing.

Chelsea’s capture of former-Arsenal midfielder Cesc Fabregas was slightly surprising. The Spanish international midfielder was surplus to requirements at Barcelona, where new boss Luis Enrique is implementing major changes.

Fabregas contributed eight La Liga goals last season, but more importantly got 13 assists in the Spanish top-flight for the Catalan giants. It was not his best season in a Barcelona shirt and he was expected to depart the Nou Camp.

Once he let it be known that his preferred destination was England, it seemed that he would return to former-club Arsenal next season. However, the Gunners had other areas of the team to strengthen and the Gunners loss is Chelsea’s gain.

Fabregas is a proven Premier League midfielder who can play in a variety of roles and who is unlikely to need time to settle in at the club, considering he has spent more of his professional life in England than his homeland.

Maybe the key signing of the summer for Chelsea was that of Spanish international striker Diego Costa from Atletico Madrid. The Blues had long been linked with a move for the Brazilian-born star and finally completed a deal worth around £32million after a protracted transfer saga.

Costa should be the missing piece of the Chelsea jigsaw next season. We all know about Chelsea’s strikers struggles last season, with trio Samuel Eto’o, Fernando Torres and Demba Ba scoring a measly 19 goals between them in 68 top-flight appearances.

In comparison Belgium playmaker Eden Hazard managed to score 14 goals and still have time to provide seven assists. Mourinho knew Chelsea’s need for a new striker was great and it was their biggest weakness last season, so the signing of Costa makes sense.

Costa found the net 27 times last season for Atletico and helped the club from the Spanish capital claim their first domestic title in 18 years. He obviously knows where the goal is, despite his poor performance at the World Cup with Spain.

Costa went into the World Cup off the back of a niggling injury, which even made him a doubt for the tournament. However, in his first two games for the Blues he has looked sharp and should be a good signing.

Veteran striker Didier Drogba has returned to the club. The Chelsea legend is only likely to play a bit-part role. However the Ivorian still has a bit of gas left in the tank and he may well prove a crucial signing at the end of the season.

Favourites

Chelsea’s summer business, especially the signing of Diego Costa has made the Blues favourites for the Premier League title. On paper their business does look good, but one fear remains that if Costa gets injured then Mourinho will have to rely on the confidence-shot Torres and the aging Drogba to lead his front line.

Are you impressed by the business that Chelsea has done this summer?