Romelu Lukaku and Roberto Martinez
Lukaku has scored 15 goals in all competitions this season.

Chelsea striker Romelu Lukaku's future will not be decided until after the World Cup finals, with Everton boss Roberto Martinez keen to take the Belgian international on a second loan spell.

Lukaku has netted 15 goals in all competitions this season for The Toffees, who will play Europa League football next season after being assured of a fifth place finish in the Premier League with a game remaining.

Jose Mourinho, the Chelsea manager, has attributed his side's failure to win the title to a lack of formidable strikers and though Lukaku remains on the books at Stamford Bridge, the Portuguese boss is intent on bolstering his attack with an attacker with a "killer instinct".

That will leave the future of Lukaku, who hasn't played for Chelsea since the 2011/12 season, in doubt once again despite two impressive seasons on loan at West Bromwich Albion and Everton.

Martinez believes Lukaku's future at Chelsea won't be decided until the summer and though Mourinho is keen for new faces to join the club, they could wait until the 20 year old's future is decided before moving in the transfer market.

"The reason Romelu came to Everton was for him to take a big role, take a lot of responsibility, to start playing 90 minutes and be a real brain in that forward line, and he has done that so we couldn't be happier," said Martinez.

"The parent club, Chelsea, are delighted with his progress and the player has developed an incredible relationship with our fans. His memories will never evaporate, but we will see what's next.

"We'll see what's the best thing for everyone. But everything will be in stages: how Chelsea are doing in their own squad and how that frees some players. It's going to take a bit of time and I don't think Romelu's situation is going to be resolved before the World Cup, in truth. I think it will be after the World Cup."

Though the Blues have been heavily linked with a move for Atletico Madrid striker Diego Costa, Lukaku remaining in west London in the summer transfer window could alter the club's transfer plans.

In the absence of the injured Christian Benteke, Lukaku is expected to lead the line for Belgium at this summer's World Cup finals.

Romelu Lukaku Chelsea FC