England number eight Billy Vunipola has revealed he dreams of playing in the NFL.

The Sydney-born Saracens back row, a key figure in the Red Rose's revival under head coach Eddie Jones, is committed to rugby union for the next three years, but would like to try a whole new ball game at some point after that.

"I'm at Saracens until 2019, pushing myself with regards to international honours and seeing if I can represent England. It is hard as a rugby player to talk about stuff like that (future career)," the 24-year-old told The Times.

"I really, really would like to go away and play something else. I really want to try out NFL, just push myself and give it a crack. If it doesn't happen then go home. It is a long time until then and my mum will probably read this and tell me to shut up and concentrate on one thing."

Asked if he watched the recent NFL games at Wembley, he said: "No. I actually don't enjoy watching it but I look at it, and think, 'If he can do it, I can do it'."

He added: "At the moment my focus is fully on rugby but it is something I dream about. It interests me. Their pitch is so small. That is why they are so particular about movements and where their feet are."