Legendary Arsenal striker Thierry Henry has backed Romelu Lukaku to succeed at Manchester United, saying the Belgium international deserves to test his skills at a club competing in the Champions League.

Lukaku, 24, joined United in a £75m ($98m) deal from Everton in July and scored on his competitive debut for the club in their Uefa Super Cup defeat against Real Madrid in Skopje on 8 August.

Henry said playing with better players at Old Trafford would help Lukaku take his game to the next level, but urged Red Devils fans to be patient with him as he adapts to his new surroundings.

Lukaku scored 25 goals in 37 league appearances for Everton last campaign, with only Tottenham striker Harry Kane scoring more than the Belgian.

"It's definitely a plus to have a guy like Romelu in your team," the former Gunners striker told Sky Sports. "Anything that drops in the box is usually a goal.

"The only question is how long it takes him to adapt. He's not going to be facing the same type of opposition at the weekends.

"He is going to have to develop a part of his game that maybe people have questioned in the past. Can he play in the final third when the opposition sit deep?

Romelu Lukaku
Romelu Lukaku (far right) is set to make his Premier League debut for Manchester United against West Ham Getty Images

"It will be a change for him, but I wasn't the same player at 24 as I was at 28. It comes with the habit of playing in that kind of situation, of playing with better players," Henry added.

Lukaku pulled a goal back for United midway through the second half after Casemiro and Isco gave Real Madrid a 2-0 lead in the Uefa Super Cup in Macedonia, but the Red Devils could not find an equaliser to force extra-time.

The Belgian is set to make his Premier League debut for United against West Ham at Old Trafford on 13 August.