Nadal set for spinal procedure

Rafael Nadal's doctor says the 14-time Grand Slam winner will receive stem cell treatment on his ailing back.

Angel Ruiz-Cotorro said on Monday "we are going to put cells in a joint in his spine next week in Barcelona".

The Spanish star was already sidelined for the rest of the season after having his appendix removed last week.

Ruiz-Cotorro said Nadal's back pain is "typical of tennis players" and the treatment is meant to help repair his cartilage and is similar to stem cell treatment Nadal received on his knee last year.

He said Nadal is expected to return to training in December.

Several NFL players and baseball players have received stem cell treatment. Nadal's fellow Spaniard Pau Gasol, a center for the Chicago Bulls, received stem cell treatment on his knee in 2013.

Nadal experienced severe back pain during the final of the Australian Open in January when he lost to Stanislas Wawrinka.

"(Nadal) has a problem typical in tennis with a back joint, he had it at the Australian Open and we have decided to treat it with stem cells," said Ruiz-Cotorro, who has been Nadal's doctor for 14 years.

He said stem cells were recently extracted from Nadal for a cultivation process to "produce the necessary quantities".

"When we have them we will put them in the point of pain," he said, with the goal of "regenerating cartilage, in the midterm and producing an anti-inflammatory effect."

Nadal, now 28, won a record ninth French Open along with three other titles this season before a stunning loss to teenager Borna Coric at the Swiss Indoors in October dropped him to No 3 in the ATP rankings. That tournament was only his third since Wimbledon due to a wrist injury.

A knee injury caused him to miss several months in 2012 before coming back to full strength to win 10 titles in 2013, including the US Open and again dominating at Roland Garros.

Nadal's 14 Grand Slam titles tie him with Pete Sampras on the all-time list led by Roger Federer, at 17.