SOUTH China star midfielder Leslie Santos, fearing another lengthy injury lay-off, will have exploratory surgery on his recurring knee problem next week. Santos, who had just recovered from major surgery on his left knee and highlighted his recovery by scoring a goal in a 5-0 thrashing of Rangers in September, was back on the injury list after his second match against Sing Tao on October 5. The two-time former Hong Kong Footballer of the Year said yesterday he did not know whether his knee would require major surgery until after the exploratory examination. Santos was one of several Hong Kong players at a skills demonstration at Tsuen Wan Stadium yesterday. He and teammate Au Wai-lun did not take part but were kept busy signing autographs. Au has five stitches in a badly gashed chin, suffered in South China's 1-1 draw with Kui Tan on Tuesday, but will play next week.