Which of Diego Costa and Edinson Cavani should Chelsea sign this summer?

Jose Mourinho's volatile relationship with his strikers isn't a new thing – he has regularly disapproved of those he tasks with finding him goals in recent years. It's probably traced back to the fact he is still so fond of those that led the line for him in the early part of his managerial career.

At Porto, it was Benni McCarthy that secured the Golden Boot award (with 20 goals in 23 games). "He is the kind of striker every coach wants, and I am no exception," said Mourinho in his first spell at Chelsea, while the South African was enjoying a successful opening season in the Premier League with Blackburn.

Then at Chelsea his love affair with Didier Drogba began, the former Marseille forward typifying everything Mourinho wants in a striker. He helped the club win their first league title in 50 years and became the first player to score in four separate FA cup finals.

"He was a great player, a great friend and somebody who will be part of my life forever,” Mourinho gushed last year. “He would say exactly the same about me. We created the kind of emotional links that are more than football.”

It's those lofty standards that every striker coming into contact with the self-proclaimed 'Special One' has to aspire to. Drogba and McCarthy are very different stylistically, but it's their attitude and work-rate that groups them together. When Mourinho moved to Internazionale, Diego Milito became his main man.

Ever since, he has struggled to identify a strong affiliation with a forward. Mourinho made an infamous remark about Karim Benzema when at Real Madrid: "If you can't go hunting with your dog then you have to take your cat." He rotated Benzema and Gonzalo Higuaín in much the same fashion as he currently does with his forwards at Stamford Bridge. Initially it worked, but then the players grew tired of not knowing when they would start.

It's common knowledge that the Portuguese coach is looking for a new striker to sit at the forefront of his modern Chelsea line-up. "I'm not happy with my strikers' performances so I have to try things," said Mourinho in Paris last week, when André Schürrle was deployed as a false nine.

The combination of Samuel Eto'o, Fernando Torres and Demba Ba has produced 15 league goals between them. When you consider that Manchester City's Sergio Agüero has the same total on his own, despite spending the majority of the campaign injured, it doesn't reflect well on Chelsea's forwards.

It must be equally frustrating for the players themselves – both Eto'o and Torres were among the top three strikers in the world at their best and Ba was prolific in the Premier League only two years ago. As Andriy Shevchenko and Hernan Crespo found out, Mourinho has no place for sentiment when searching for a ruthless finisher.

Many names have been linked with the job by the English media, but the stand-out candidates are Atlético Madrid's Diego Costa and PSG's Edinson Cavani. Both have a number of similarities with Mourinho's favourite prototype – Drogba.

Costa is quick, powerful, tenacious, strong, and brilliant at dribbling past defenders who know they are in a fight from the first minute to the last. Cavani is robust, clever, good in the air and superb at holding up the ball to link up with midfield runners.

If you mix their characteristics together you could easily be looking at the Ivorian frontman in his prime.

The two are special players that have earned their reputation in very different ways. Costa spent numerous seasons out on loan after arriving in Madrid in 2007. He was even sold to Real Valladolid at one point, but brought back the following season. It was his time at Rayo Vallecano in 2012 that identified his true potential, however, when he scored 10 goals in 16 appearances at Vallecas.

When he returned to the Vicente Calderón, Diego Simeone was already in the process of building his hard-working squad, and Costa's effort was perfect for the transition. He hit 22 goals last season, which led Brendan Rodgers to attempt to take him to Anfield.

The exit of Radamel Falcao to Monaco in the summer gave Costa the opportunity to be Simeone's main man. David Villa surprisingly joined from Barcelona, but it's Costa that has been the Argentine's talisman. His ability to score important goals has seen him net against Real Madrid and Milan, while he has seven goals in six Champions League appearances. The Brazilian-born striker made his debut for Spain recently in a friendly against Italy.

Uruguayan Cavani has been in France for under a year since making the move from Naples. As a more versatile forward, he has primarily found himself playing wide right with Zlatan Ibrahimovic in the centre. It's a role he has occupied for his national team, and along with Liverpool's Luis Suarez he rotates between tracking back on the wing and playing as the focal point of the side.

This adaptability is a bonus, but it's his competence as a central figure that will keep Mourinho's interest. At Napoli, he scored 78 league goals in 98 starts across three campaigns under Walter Mazzarri. At PSG, there has been a natural decline in his finishing rate, but when used as a striker in Ibrahimovic's absence he has bagged six in as many matches.

In a more possession-based set-up, he has seen his passing rate improve considerably, although his creativity needs work as he has been providing fewer assists.

Both strikers are exceptional on the counter-attack and used to working under strict tactical instructions, which are the assets that Mourinho desires the most. Their awareness of team-mates, drive with the ball and finishing capacity makes them perfect Mourinho-style forwards.

Costa has shown he can bully the lesser sides while also performing at the highest level. Cavani's scoring capability has been demonstrated over a longer period and he is more flexible. In terms of value for money, Costa will be cheaper to purchase and it's that factor that should see Roman Abramovich sending his roubles to the Spanish capital this summer. But if Chelsea opt for either Costa or Cavani in the transfer window, there should be far fewer complaints from Mourinho next season.