Jamaican sprint champ Usain Bolt wants a trial with Manchester United.

Bolt has already dabbled in football, giving sprint training to Cristiano Ronaldo during pre-season at United a few years ago.

"People think I am joking when I say that I would like to play for Manchester United," said the Jamaican.

"But if Alex Ferguson called me up and said, 'OK, let's do this, come and have a trial and see if you are good enough' it would be impossible for me to say no."