The unorthodox healing methods being used by several Premier League footballers have not convinced sports injury specialist Dr Conor O'Brien, it has emerged.

Speaking to the Irish Times, the physician from the Sports Surgery Clinic in Dublin said there is no evidence to suggest that Mariana Kovacevic's horse placenta treatment has any medical value.

Ms Kovacevic, a Serbian physiotherapist, has recently treated injured football stars such as Arsenal striker Robin van Persie and Yossi Benayoun of Liverpool with a procedure that involves massage with a horse placenta.

"When you look at the hard data, there is nothing in a placenta that would confer any greater healing power than the existing medicines," Dr O'Brien told the newspaper.

"Normal injuries take a definite time to get better."

Van Persie was the first Premier League player to publicise the treatment, as he headed to Serbia after suffering an ankle injury while playing for the Netherlands earlier this month.

People who prefer less unusual treatments may consider ultrasound machines, which can reduce pain and accelerate healing for sports injuries.