Riewoldt injured his left foot when he was tackled to the ground by Geelong's Tom Lonergan while trying to kick the ball in the third quarter of the Saints' 101-point loss to Geelong at Simonds Stadium.
He had scans on Sunday morning and said he hoped to be able to play against the Brisbane Lions next Saturday night at the Gabba.
"It's probably not as bad as we first thought," Riewoldt told 3AW on Sunday afternoon.
"I chipped a bit of a bone spur off so that's just floating around inside my foot.
"The prognosis is good and I should be able to get up for next week."
Defender James Gwilt will be assessed this week after suffering suspected bone bruising on the knee he had reconstructed in 2011.
He was subbed out in the second quarter and will have scans in the coming days.
Veteran Saint Lenny Hayes also hurt his hamstring.
After the game, coach Scott Watters said all three were unlikely to face the Lions but Riewoldt was more optimistic after getting the results of his scans.
Jennifer Phelan is a reporter for AFL Media. Follow her on Twitter @AFL_JenPhelan
