The Manly speedster suffered the injury playing against the Rabbitohs last week and is expected to miss four to six weeks.
The Sea Eagles will now face an injury-depleted Newcastle with a key injury of their own. They will now be forced to fill Koula's spot, who marks up against Newcastle's own star centre, Bradman Best.
With Koula out of the way, Morgan Harper will likely get his first chance in the maroon and white for the season. Having featured on the wing for the Maori all-stars in their match against their Indigenous counterparts, Harper has been unable to break into the top grade since.
Harper will have some big boots to fill when filling in for Manly's dominant strike centre, with the side losing significant speed without the Tongan international. Despite having a relatively quiet start to his season Koula's absence will bring a noticeable change to the tempo on the right side.
However, it proves as a good chance for Harper to establish himself as a consistent first grader as some good performances could cause a headache for coach Anthony Seibold when Koula returns from surgery.
Koula is yet to score a try or manage a try assist on Manly's right edge this season, opening the door for Harper to impress in his return to NRL.
Playing 18 games in the 2022 season Harper is no stranger to first grade and will need to make the most of his opportunity, should he wish to compete for an NRL jersey with Brad Parker and Koula in the future.
Still expect the Sea Eagles to use Harper as a solid attacking option, running alongside in-form back-rower Haumole Olakau'atu as another strike player.
Manly will be looking to bounce back from their golden point loss last week against a depleted Knights side this Saturday in Mudgee.