Results of scans taken this morning reveal that Trbojevic has a syndesmosis injury to his left ankle, which is not to the extent as originally thought.
He also has an MCL (medial collateral ligament) sprain to his left knee.
Trbojevic will be out for six to eight weeks.
“We feel extremely lucky given the nature of the mid-air tackle as it had the potential to be a lot worse,’’ said Manly Coach Trent Barrett.
“To lose Tom for up to eight weeks is very disappointing. However, we aim to continue to play well and improve our position on the table.
“Tom will now begin his rehabilitation program with the Manly medical staff.”