Everton boss Roberto Martinez has backed star striker Romelu Lukaku to develop into one of the world’s best forwards, despite his mixed campaign for the Toffees.

Having impressed while on loan at Goodison Park during the 2013-14 campaign, Everton broke their transfer record to sign the 21-year-old for £28million last summer.

However, the Belgium international has flattered to deceive at times this term, struggling in the first half of season before finding a bit of form at the start of 2015.

Despite missing nearly a month recently with a hamstring injury, Lukaku has now scored 18 times in 46 appearances for Everton this season.

Martinez believes the former Chelsea youngster is over whatever was holding him back in the early stages of the season and says he continues to see signs of him developing into one of the world’s finest strikers.

“We’ve all been through that type of season,” Martinez said.

“He is quite responsible and sometimes takes a critical view of himself but I think that’s what will make him one of the best strikers in world football.”

Lukaku’s own form has mirrored that of Everton’s this season, the Merseysiders struggling to get going in the first part of the campaign before putting a decent run together.

Martinez believes it has just been one of those seasons for his men and is confident they will improve next term.

“As a team we have been tested this season and individually there has been a point where you have to push yourself through, learn from the experience and become a proper performer for the team,” he added.

“Now everyone is ready to be on the pitch and help the team and Romelu’s form since January has been really strong.”

Everton face a tough test of their recent resurgence on Sunday when they face Manchester United at Goodison. The home side are 3.50 for the win, with United 2.20 and the draw 3.30.