The 24-year-old, a key middle-order batsman, tore ligaments in his left knee playing on the eve of the Champions Trophy clash against eventual winners Australia in Mohali on Oct. 29.
"It will be touch and go for the World Cup because of the length of time it takes to recover from such an injury," Andrew Leipus, consultant physio with the Indian board, told Reuters.
"My understanding is he will have to undergo surgery as the torn ligament needs to be reconstructed," Leipus said.
The injury seems to have sidelined the left-handed batsman for the South Africa tour starting on Nov. 19. He has already been ruled out of the one-dayers, which will be played first.
Leipus was India's physio for five years until 2004 and now works as a consultant.
The orthopaedic surgeon Anant Joshi will examine Yuvraj again next week when a decision on his treatment is expected to be made.
The Punjab player, who has featured in 159 one-dayers and 19 tests, has grown in stature as an aggressive batsman and superb fielder in the point region.
He was nominated for the ICC One-day Player of the Year award, which was won last week by Australia's Mike Hussey.