Saintswrath

According to NOLA.com

Chris Ivory (knee) is expected to miss about two more weeks.

This is a tentative timetable as there have been rumors that Ivory could be back sooner. But with Ladell Betts being signed, chances are that the Saints don't expect Ivory to return by Week 4. He's a weak roster stash at this point.
Saints released RB DeShawn Wynn.
It's a strange move, but the Saints apparently feel more comfortable with Ladell Betts than Wynn. It could also be a sign that Chris Ivory (knee) is closer than previously reported to returning. Betts is now Pierre Thomas' backup for the week's game against the Falcons.

UPDATE:
Saints RB Chris Ivory (sprained MCL) is expected to resume practicing "soon," according to the New Orleans Times-Picayune.

It's not expected to be this week, but Ivory could at least get in some practice time in preparation for a Week 4 return. Impressive with his quick pickup of the offense and big-play ability in the preseason, Ivory is a better stash for Pierre Thomas than Ladell Betts with Reggie Bush out 4-6 weeks.

Reggie Bush should recover from his broken leg for the second half of the season | NOLA.com