In a near worst-case scenario for the Sea Eagles in Auckland, their two main men limped from the field late in Friday night's loss and did not return.
Manly coach Anthony Seibold said Trbojevic had suffered "tightness", and the Sea Eagles have since confirmed to AAP the issue was in the fullback's left hamstring.
Officials were insistent on Friday night he was only taken off the field as a precaution, with the fullback having suffered six hamstring injuries in the past.
Cherry-Evans then left the field shortly after Trbojevic with seven minutes to play, collapsing to his knees in defence and clutching at his lower back.
"Chez had a little back spasm there, so he needs to get checked," Seibold said.
"And Turbo was feeling a little bit of tightness so we need to get both of them checked.
"I've only spoken to them briefly and I haven't spoken to the doctor yet."
Any long-term injury to either of the pair would be a significant blow to Manly, with the duo at the centrepiece of so much of their attacking power.
Trbojevic had only spoken in the past week about the way he had benefited from an injury-free run, and had started the season in rare form against North Queensland last week.
Medical staff will decide on Saturday if the No.1 requires scans, depending on how he pulls up.
Meanwhile, 36-year-old Cherry-Evans is weighing up his future beyond this year, having had a charmed run with injuries before his career.
Even before the duo's problems Manly had been off their game, as Warrior Luke Metcalf helped lay on three tries, scored one of his own, and landed six from six conversion attempts.
Playing through the pain of a broken nose, Metcalf answered his critics from the Warriors' opening-round loss to Canberra in Las Vegas with a dominant showing back at home.
"It was really unfair around criticism considering we didn't tackle well or run the ball well last week," Warriors coach Andrew Webster said.
"So we didn't give him opportunities, but tonight he was really good off the back of a platform.
"You could see him really building confidence and getting into the game tonight. I thought he handled the mental occasion of this week really well."
Manly looked as if they were going to carry on from their opening-round thrashing of North Queensland when Trbojevic finished off a long-range try in the third minute.
But the Sea Eagles again showed consistency away from home is their achilles heel, appearing a completely different side from that point on.
All three of the Warriors' first-half tries came off the back of Manly errors, while almost 80 per cent of the ball was played in the hosts' attacking half.
That allowed Metcalf to put on a show, proving there can be life in the Warriors' No.7 jersey after Shaun Johnson's 2024 retirement.
The halfback laid on a perfect short ball for one Ali Leiataua try, while he and Chanel Harris-Tavita combined for another before halftime.
He also threw the last pass for a Taine Tuaupiki four-pointer, allowing the winger to cut back inside and step through Manly's broken defensive line.
And while Manly twice clawed back within eight points in the second half through two marginal tries being approved by the bunker, a comeback always looked a bridge too far.
The Sea Eagles' fate was sealed when Roger Tuivasa-Sheck capped an impressive night by forcing his way over, before Metcalf scored his late try.
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