MADRID (AP) -- Seve Ballesteros will undergo a fourth round of chemotherapy as he continues treatment of a cancerous brain tumor.

Ballesteros said Thursday that blood tests from his third round of chemotherapy showed he could continue with the treatment, with the next round scheduled to begin Saturday.

The five-time major winner underwent three surgeries following a biopsy after being admitted to La Paz Hospital in October, shortly after fainting at Madrid's Barajas international airport.

Ballesteros said his spirits were "still high," although the 51-year-old golf great did not mention the possibility of a public appearance that he'd been planning to make.

As a player, Ballesteros was known for spectacular shots and improvisational play to win three British Opens and two Masters. He also recorded 50 victories on the European Tour and is widely recognized as having transformed European golf.

After lobbying to have the Ryder Cup expanded to include continental Europe in 1979, Ballesteros helped beat the United States in 1985 to begin two decades of dominance. He also captained Europe to victory in 1997 at Valderrama, Spain.

Ballesteros retired in 2007 because of a long history of back pain and has since concentrated on golf course design.

Copyright 2009 Associated Press. All rights reserved.