Belgium manager Roberto Martinez has claimed that Everton ace Romelu Lukaku has still got enough in him to become the best out-and-out striker in world football.

The 23-year-old has found the net on a consistent basis throughout his career to date, scoring 17 goals while on loan with West Bromwich Albion and 18 during a similar stint with the Toffees.

Lukaku has since made his move to Goodison Park permanent, racking up a further 39 goals in the last two campaigns to become the club's all-time leading scorer in the Premier League.

Martinez, the man to land Lukaku on a long-term deal in 2014, believes that there is still more to come from the former Anderlecht starlet in the coming years.

"He always wants to do more in training. At a very young age he had an incredible goal scoring threat," he told BBC Sport. "Any footballer who is special at the highest level you have to be outstanding at something; Rom it's the goal scoring threat that he carries.

"From the age of 21 to the age of 23 now he's changed a lot. He wants to improve, he works on his hold-up play, he works on using his body, he's been working on his movement in the box. But what he's never ever lost is the outstanding quality of scoring goals.

"If you look at the facts there at the age of 23 I think he's got the possibility of becoming the best number nine in world football. He's got absolutely everything."

Lukaku may be on his way out of Everton at the end of the season after recently admitting that he wants to play Champions League football.