The 29-year-old will be rested from training for the next two to three weeks as he overcomes the severely bruised back he suffered against Port Adelaide on Saturday.
Schneider was kneed in the lower back in the practice match against the Power and didn't finish the game.
He was absent from the Saints' season launch on Thursday night.
While he doesn't need surgery, he has suffered severe bruising and some bone damage in his lumbar spine.
The expectation is he will return to training early next month.
It's a blow for the veteran who, apart from a hamstring setback after Christmas, has put together a decent pre-season.
It also removes another experienced player from the round one line up, with a number of first-choice stars already set to miss.
The Saints will be without Jack Steven (foot), Lenny Hayes and Leigh Montagna (suspension) and Sam Gilbert (foot) for the season opener.
Steven is progressing well from the fracture he sustained in his right sesamoid bone late last month.
While he will miss the start of the season, he attended the season launch without a moon boot or cast.
He walked aided by crutches but was putting weight through the injured foot.
Rookie Eli Templeton is in the frame to be upgraded next week given the depleted midfield.
Twitter: @AFL_JenPhelan
