With the Sea Eagles in control of the game and up 34-12 , Trbojevic left the field carrying his right arm and with blood splattered across his face with 16 minutes left.
The Manly superstar appeared to have his right arm stretched when attempting to make a tackle on Jacob Preston, before teammate Luke Brooks landed on it.
Trbojevic looked devastated as he left the Accor Stadium field, having had a woefully unlucky run of injuries in recent years. Â He appeared to have his arm in a sling after the match.
Making matters worse for Manly, winger Jason Saab also suffered a syndesmosis injury early in the match after a Bronson Xerri hip-drop tackle.
The injuries marred an otherwise perfect night for Manly, who made another real statement against one of the competition's in-form teams.
In front of a record crowd for a 6pm game outside of Magic Round of 35,502, Manly piled on the most points of any team against the Bulldogs this year.
Luke Brooks was superb just two weeks out from his long-awaited first finals series, but had a minor scare after being put on report for a dangerous throw.
The five-eighth set up one try when he toed ahead a Haumole Olakau'atu offload, regathered and put Trbojevic away on his inside to score.
Another try came when he looked out the back and went short to Karl Lawton before the break, allowing the second-rower to go under virtually untouched.
And when Manly led 24-12 at the break, it was a one-on-one strip from Brooks that put the Sea Eagles back on the attack for Lehi Hopoate to cross.
Olakau'atu was also superb in the second row for Manly in attack and defence, while Matt Lodge, Taniela Paseka and Nathan Brown were immense in the middle.
Hopoate was also influential, scoring a double and both times making use of limited space to get to the line.
In comparison, this was the Bulldogs' worst game in months.
They were able to stretch Manly down the right edge multiple times, but two errors on attack before halftime and an obstruction after the break proved costly.
Matt Burton also finished the game with a concussion, meaning he won't play North Queensland next Saturday night at Accor Stadium.
Canterbury must now win that game to wrap up a home final, or else risk having Manly go over the top of them if the Sea Eagles beat Cronulla.
That task now appears far more daunting without Trbojevic.
He cut a dejected figure in the sheds and on the sideline late in the match, after it was revealed this week he attempted to take a pay cut after his last injury in May.
The fullback suffered a shoulder injury in 2022, but that was to his left arm. He also sustained an injury to his right pectoral muscle last year.
11°C