Madrid  - Former professional golfer Severiano Ballesteros will undergo a second operation on his brain, doctors at a Madrid hospital said Thursday.

The 51-year-old had developed an oedema as well as a haemorrhage on his brain, they said, describing his condition as serious but stable.

During the operation on Friday doctors will also be removing some more of the tumour which had already resulted in an operation last week, but which could not be removed as it was in parts of the brain which were not easily accessible.

The winner of five majors fainted on October 6 at the Madrid airport and was then diagnosed with a brain tumour.

The former Ryder Cup captain retired from golf last year after winning 87 tournaments, including three British Opens, as well as two US Masters. (dpa)