Spain's Rafael Nadal shows his frustration during the Australian Open quarter-final against Croatia's Marin Cilic yesterday. Pic/Getty Images

Rafael Nadal called on tour organisers to do more to halt injuries to top players after heartache at the Australian Open as he pulled out of his semi-final yesterday.  The Spanish World No. 1 retired with a muscle injury while trailing 0-2 to Marin Cilic in the fifth set of a titanic quarter-final struggle on Rod Laver Arena. The look on Nadal's face said it all as he came to terms with missing a big opportunity to go after his 17th Grand Slam title.