The hospital says it intends to release no new statements on the his state until Monday'or later'unless there is a change in his condition.
Ballesteros underwent a 6 1/2 -hour operation Friday on a cancerous brain tumor, a procedure which the hospital said went better than expected.
The operation removed the rest of the 51-year-old Spaniards tumor and reduced the swelling on his brain. The hospital said Ballesteros was taken to the intensive care unit following the operation where hospital specialists will keep him under close observation.
Ballesteros was admitted to the hospital Oct. 6 after briefly losing consciousness at Madrids international airport. Eight days later, a sizable part of the tumor was taken out.
Ballesteros tumor is an oligoastrocytoma, which affects cells that cover and protect the nerve cells in the brain and spinal cord. In an earlier operation, part of his skull was removed to allow room for the swelling brain to expand.
Ballesteros won the British Open three times and the Masters twice. He captured a record 50 tournaments on the European tour before retiring last year because of a long history of back pain. He has since concentrated on golf course design.
Ballesteros revolutionized European golf. After the Ryder Cup was expanded to include continental Europe in 1979, he helped beat the United States in 1985 to begin two decades of dominance. He also captained Europe to victory in 1997 and teamed with Jose Maria Olazabal in one of the most formidable partnerships in Ryder Cup history.