Himesh Patel was ''pleasantly surprised'' by Ed Sheeran's ''great work ethic'' on set for their film 'Yesterday'.

The 28-year-old actor is starring opposite the 'Shape of You' hitmaker in the upcoming Danny Boyle-directed movie, which follows Himesh as struggling musician Jack Malik who one day wakes up to discover he's the only person who knows The Beatles and can remember their songs.

Himesh insists that Ed, 28, has the hardest role of all the cast because it's a bigger ''challenge'' to portray yourself on screen.

In an interview with The I Paper, he said: ''I was surprised, pleasantly surprised, and he clearly has a great work ethic. And he brought that to the challenge of doing this. It's not easy to play yourself - perhaps it's even harder.''

Ed allowed scenes for the film to be shot at one of his sold out 'Divide Tour' Wembley Stadium concerts and Himesh got the chance to step on stage just like the musician did.

Director Danny, 62, admits it was an ''extraordinary'' event to ''witness'' from the performer's side.

The filmmaker said: ''It's just extraordinary to witness. One man ... he's got 80,000 people in the palm of his hand every night.''

Himesh came on stage after Ed departed and admits there were only a few hundred people left in the huge stadium when he stood in front of the mic to sing.

He said: ''I can now say I played two nights at an empty Wembley Stadium.

''I did ask him early on and he gave me this very funny advice about playing to the blob. He connects really well with his fans - they give him so much. But sometimes it starts to feel overwhelming, and it becomes a blur ... and he plays to the blob.''