Ganso out for six months
Ganso, who made his Brazil debut in a 2-0 friendly win over United States this month, damaged his anterior cruciate ligament and cartilage during Wednesday's Brazilian championship match against Gremio.
"Recovery will take about six months. He'll start physiotherapy on Monday," club doctor Rodrigo Zogaib told the Santos website on Thursday.
The 20-year-old Ganso and teenager Neymar, who turned down a 20 million euro offer from Chelsea, helped Santos win two titles in the first half of the season - the Paulista (Sao Paulo) state championship and the Copa Brasil.