Liverpool's injury crisis has become more serious after Yossi Benayoun and Albert Riera were ruled out for three to four weeks yesterday (November 12th).

Both midfielders were substituted in the Premier League side's 2-2 draw with Birmingham City at Anfield on Monday night and have been diagnosed with leg muscle injuries.

Benayoun and Riera join a lengthy injury list for Liverpool, with star striker Fernando Torres currently undergoing treatment on a persistent groin problem.

In addition, defender Daniel Agger experienced back pain in the Birmingham match and opted not to join up with the Denmark squad for the upcoming international friendlies.

However, manager Rafa Benitez said that he expects Agger to be back in training by the end of the week.

Liverpool are now 11 points adrift of leaders Chelsea in the Premier League, having won just one of their last nine games in all competitions.

Ultrasound can help to accelerate healing for sufferers of back pain and muscle strains, as it penetrates the skin's surface to stimulate soft issue and reduce swelling.