Having refrained from dipping into the January transfer market, Antonio Conte is determined to bolster his squad this summer, as Chelsea prepare to re-enter the Champions League and maintain the kind of form that has taken them to the top of the Premier League this season.

Chelsea’s main priority will be to sign a striker, with Michy Batshuayi ultimately failing to provide any competition for their well-established leading man, Diego Costa.

The club appear to have two key targets in this regard. Conte, who has reportedly been assured that he will be in the ‘driving seat’ when it comes to transfers this summer, favours a move for Real Madrid’s Alvaro Morata, while the club’s director Marina Granovskaia and technical director Michael Emenalo are thought to favour a move for Everton’s Romelu Lukaku.

But who should Chelsea target? We have compared Morata and Lukaku – along with Costa – in five key areas, to find out where Chelsea should focus their attention.

Where next for Romelu Lukaku? Show all 6 1 /6 Where next for Romelu Lukaku? Where next for Romelu Lukaku? where-next-for-romelu-lukaku.jpg Lukaku stunned Everton when he rejected the offer of a contract extension after a training session, but where will he go now? Getty Where next for Romelu Lukaku? chelsea.jpg Chelsea are in need of another world-class striker, especially given Diego Costa's volatile nature. Lukaku is a self-confessed fan of the club and idolizes Didier Drogba, but would he return to the club which failed to give him a chance? Getty Where next for Romelu Lukaku? manchester-united-1.jpg A move to United perhaps makes the most logical sense. But any approach from United hinges on their summer pursuit of Antoine Griezmann, while Jose Mourinho has previously criticised Lukaku's "mentality and approach". Getty Images Where next for Romelu Lukaku? psg.jpg Following PSG's dismal capitulation in Barcelona, there is an appetite in the French capital to revolutionize the squad ahead of the new season. PSG have the cash to afford Lukaku, but it remains to be seen whether the Belgian would be happy moving to a less competitive league. AFP/Getty Where next for Romelu Lukaku? juventus.jpg The Italian champions are desperately trying to assert themselves on the European stage once again and crave a marquee signing this summer. But Juventus would only be able to afford Lukaku if they first cashed in on their talented young forward Paulo Dybala. Getty Where next for Romelu Lukaku? china.jpg Interest from teams in the Chinese Super League is guaranteed. But given Lukaku's determination to play in the Champions League, it is high unlikely he would follow the likes of Oscar and Hulk to the Super League. AFP/Getty

Strike-rate

There’s no arguing with Lukaku’s prowess in front of goal. The striker has hit double figures in his last five seasons in the Premier League and currently leads the top goalscorers table, two ahead of Tottenham’s Harry Kane and three ahead of Arsenal forward Alexis Sanchez.

Lukaku is the leading Premier League goalscorer this season (Getty)

Costa lags behind on 17 goals this season but, since the Spaniard arrived in London three seasons ago, his strike rate has been dead level with Lukaku’s. Both men have scored 49 goals in two and a half campaigns – although it’s worth pointing out that Lukaku has played in more games.

Morata, handed a largely bit-part role by Zinedine Zidane this season, has only scored eight league goals so far this campaign and generally scores far less than either Costa or Lukaku. Excluding his first three seasons in professional football playing for Real Madrid B, he has never scored more than eight goals in a league campaign.

Build-up play

Not only is Lukaku the Premier League’s leading goal-scorer, only nine players in the Premier League have made more than his six assists this season. He also averages more key passes than either Costa or Morata this season, although he is prone to giving the ball away, suffering from the lowest pass success percentage of the three.

Morata is less tidy with the ball at feet (Getty)

Like Lukaku, Costa’s attacking influence isn’t just restricted to scoring. He has notched up five assists this season, averages over 30 passes per game and only Alexis Sanchez and Zlatan Ibrahimovic average more than the 10 successful through balls he plays per match.

Morata is less integral to his team’s build-up play. He has two assists this season and averages less than a third of the passes made by Costa. He did manage seven playing for Juventus last season, but that number still lags behind both Lukaku and Costa.

Lone striker role

Conte’s 3-4-2-1 requires a powerful target man comfortable playing with his back to goal and adept at attacking crosses knocked into the box by the team’s marauding full-backs.

Conte likes playing with one central striker (Getty)

Lukaku is adept in both regards. He wins an average of 3.6 aerials per game – significantly more than either Costa (1.3) or Morata (0.8) – and has scored 5 goals with his head this season, the second highest number this campaign.

Impact

As demonstrated by his excellent scoring record both in the Champions League and at Euro 2016, Morata tends to deliver in the big games. He was joint second in the top goalscorers chart in France last summer and memorably levelled the scores in the 2015 Champions League final between Juventus and Barcelona.

Morata has also done well this season to make the most of the limited opportunities Zidane has handed him. He has only started eight La Liga games thus far but managed to score in half of those, with his other four goals coming in late match cameo appearances.

Costa is guaranteed to make a nuisance of himself whatever the game (Getty)

For all his talent, there meanwhile remains something of a suspicion that Lukaku is a flat-track bully, who only truly makes his presence known against struggling teams when the odds are already firmly stacked in Everton’s favour. That’s not entirely fair, but it is striking that – in real terms – Lukaku’s 21 goals have only won Everton seven points this season.

And after 132 Premier League appearances for the Toffees, Lukaku is still waiting to score the winning goal against a team positioned in the top four.

Price

Chelsea will likely have to make Diego Costa one of their top-earners this summer if they are to fend off interest from Atletico Madrid, as well as clubs in the Chinese Super League. A five year deal totalling £57m has been rumoured. Compared to signing either Lukaku or Morata, that remains the cheapest option.

The Belgian is the most expensive option (Getty)

Lukaku’s transfer fee generally depends on when Chelsea attempt to sign him. Make their move this season and they can expect to pay a premium, with Everton likely to demand a fee in the region of £65m. But that valuation will drop next summer, when Lukaku enters the closing stages of his contract.