They were once division rivals. That was more than a decade and scores of players ago. The 49ers and the Saints are less-frequent rivals now - but no less bitter ones.
In the 2011 NFC Divisional Playoff game the 49ers scored a touchdown with nine seconds left to end the Saints' Super Bowl hopes in what has been their last playoff appearance.
A year ago, the 49ers came to New Orleans beat and beat up the Saints in snapping a six-game regular season losing steak to their former NFC rivals.
They return to the site of their loss in Super Bowl 47 coming off their worst performance of the season while losing at home to Carolina while the Saints lie in wait coming off their best performance of the season this past Sunday night against Dallas.
The Saints offense figures to have a far tougher time a week later. San Francisco boasts the best quartet of linebackers in the NFL and a defense that is equally stingy against both the run and the pass.
It's the imbalance of the 49ers offense that the seventh-ranked Saints defense will try to exploit. The 49ers come here with quarterback Colin Kaepernick coming off the worst game of his nascent starting career. The 49ers are dead last in the league in passing and dead last in third down passing. But the Niners have proven they can win without much production from Kaepernick. In a pair of victories he had less then 10 completions in each. You might remember, however, that Geno Smith didn't complete 10 either as the Jets beat the Saints.
So the key for the Saints who are tied for last in the league in giving up 5 yards per rush would seem to be holding running back Frank Gore in check. Gore has averaged 92 yards and more than 5 yards per carry in his last four games against the Saints.