Specialist Orthopaedic Dr Kalyan Mukherjee, who advised the medical test on Friday, said "Sourav's medical reports confirmed that the injury is not serious."
Ganguly had undergone an MRI scan, digital X ray and blood test at Eko X-ray Centre in Kolkata on Friday to assess the nature and extent of his injury.
"The reports confirmed my diagnosis and there is no bone injury but only the ligament was affected," Mukherjee said.
Ganguly was advised normal rest at his residence and asked to do swimming and some exercise.
While the doctors said that there was 80 per cent chance of his recovering fully before the final Test, the skipper himself felt definite improvement in the condition of his injury and was confident of Ganguly's fast recovery to be able to lead the side in Rawalpindi.
The left-hander flew to Kolkata on Thursday evening for treatment after watching the Rahul Dravid-led Indian team register a historic first Test victory against Pakistan ontheir soil at Multan.
The Indian skipper injured his back while fielding during the fifth and final One-day match at Lahore on March 24 and was ruled out of the first Test at Multan. As his injury could be healed before the third Test, he would miss the second Test beginning at Lahore on April 5.