The Titans will meet the Broncos at Cbus Super Stadium on Sunday, with the winner advancing to the NRLW grand final.
Phoenix-Raine Hippi will not be available after scans confirmed a collarbone injury suffered against the Knights.
The 20-year-old left Newcastle's final regular-season match in the 14th minute and will miss the preliminary final.
Further medical assessment will determine when Hippi can return.
Fanua Rimoni has recovered from the flu and is expected to contribute during the finals series.