Diego Costa
Diego CostaReuters

Chelsea are preparing a move to sign Atletico Madrid star Diego Costa and Bayern Munich striker Mario Mandzukic at the end of the season, according to the Express.

The Blues have the services of Fernando Torres, Samuel Eto'o and Demba Ba as the first choice strikers in the squad. Jose Mourinho is keen on strengthening his strike force and has already admitted the west London club will be looking to bring in a striker with killer instinct.

"We have good players, but we don't have the kind of striker able to, in a short space, to make an action, to score a goal, to open the gate. In these kind of matches you just need to open the gate. When you open the gate, the gate is open and you go on to win much more," Mourinho told Chelsea TV.

"We weren't able to do that. We have to try to win as a team, to improve as a team, but also add the attacking player with that killer instinct and the number of goals that push teams to different levels. It's something our club is going to try [to do], respecting obviously that we have good strikers."

The Express report says the former Real Madrid boss has set his sights on signing both Costa and Mandzukic in the summer transfer window. The Portuguese tactician is looking to bolster his strike force by making a £57m bid for the two strikers.

Atletico's hitman has been in fine form for the Spanish capital club this term, scoring 27 goals in the league. Meanwhile, Mandzukic has managed 18 goals and four assists in 29 league appearances.

Mourinho is looking to allow Eto'o, Torres and Ba leave Stamford Bridge at the end of the season and make way for Costa and Mandzukic to replace them in the squad. The Blues manager has already informed Chelsea owner Roman Abramovich to meet the Brazilian-born Spanish striker's £32m release clause.

The west London club's manager is also looking to make a £25m approach in acquiring the services of Mandzukic in the summer. Bayern has already agreed terms in signing Robert Lewandowski and the German champions could be tempted to allow the Croatian international leave in the coming transfer window.

A move for Costa and Mandzukic in the summer is likely to strengthen Chelsea's attacking division and will help them do well in all competitions next season.