Jones sustained the injury in a clash with David James in the early stages of Trinidad and Tobago's friendly with England earlier this month.
Initial assessment was inconclusive as to the extent of the injury, but Sunderland have revealed that after their own investigations, â€˜conservative treatment' on the player's knee will be required.
The club's website reported: "The club arranged their own radiological investigations and have detected ligament damage, which will require several weeks of conservative treatment. After this period, a further assessment will be undertaken to assess the full extent of the injury."
After joining the Black Cats from Southampton, Jones established himself as one of Roy Keane's â€˜untouchables', and was hailed by his manager as one of the Premier League's best strikers.
Keane must now reconfigure his plans and find a replacement for his star player. Daryl Murphy, Michael Chopra and Rada Prica all featured up front for Sunderland last season but none could dislodge Jones from the side.
The club have been recently linked with an Â£8 million move for Tottenham Hotspur misfit Darren Bent, and must now step up their efforts in pursuit of a forward.