It'll be Spencer Rattler, not Jake Haener, taking the field as the New Orleans Saints' backup quarterback on Sunday night against the San Francisco 49ers. Rattler was seen warming up with the second-team offense and will take over for Carr once the starters call it a night.

This was expected, but that doesn't make it any less exciting. The rookie led a game-winning drive in last week's preseason action and now he gets an opportunity to show what he can do with the second-string offense instead of the third-stringers.

Let's see how he performs against one of the league's better teams, even if he's running against other backups. Rattler has been pushing Haener for thee backup job all summer and a big day at Levi's Stadium could help his case  to back up Carr this year.

Haener has been ahead throughout training camp but Rattler's natural arm talent and polished mechanics have cut into the second-year pro's lead. If Rattler can improve on his decision-making and work out some bad habits like dropping back too far under pressure, the sky is the limit for him.

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This article originally appeared on Saints Wire: Spencer Rattler, not Jake Haener, will take the field as Saints' QB2 vs. 49ers