"If we can't and Jack can't put up with the pain anymore then it's another decision - but that's all for the future.
"We just want to give him some pain relief."
England international Reed had been named for the Raiders clash but was a no show at Wednesday training.
He has been replaced at left centre by Jordan Kahu with Greg Eden filling the right wing vacancy.
Bennett said Reed would undergo scans and an arthroscope in the coming days. "He's in pain all the time whether he is sleeping or sitting around," Bennett said.
"No one here has been putting him under pressure to play.
"He didn't want to let the boys down.
"But for him it was getting worse not better."
The injury explained Reed's form slump.
He had been on a 10-match try drought - the second longest of his 128-game career.
Brisbane have lost three straight and are battling to keep in touch with the top four during another gruelling State of Origin period.
They will be shown no mercy by a Canberra side buzzing from three straight wins. Asked if he was feeling the weight of expectation, Bennett said: "No, I just feel the weight of letting people down.
"I hate letting people down. I feel embarrassed."
Bennett said juggling representative players was as challenging as ever, as six of his players prepare for their third game in eight days.
"The (Origin) players are tremendous, they want to come back and play - they see it as a badge of honour," Bennett said.
"I just need to find a balance."
- AAP
