"We're looking at it, and I think for us to be as good as we can be, he's got to save games for us," Duncan said. "And I think [manager Tony La Russa] feels the same way."
Franklin was reluctant to discuss the change until he knew that the coaching staff had confirmed it, and Isringhausen had little to say of the matter. But with Franklin in a deep slump and Isringhausen pitching well more often than not, the decision was made to change the two right-handers' jobs.
"I personally see improvement in the way Izzy's throwing the ball," Duncan said. "If I didn't think he could go out there and get the save, I certainly wouldn't agree -- not that it would make any difference, but my opinion wouldn't be what it is."
Franklin had no complaints with the decision.
"In my head, I knew Izzy's the closer and I'm just here to fill in until he got ready," Franklin said. "When he's ready, which I think he is, everybody knows their roles and that's when I think our bullpen is the best."
Isringhausen has been the Cards' man in the ninth since he joined the team in 2002, but he was displaced from the job after a wicked slump early in the year. He was placed on the disabled list with a hand laceration, and since returning from the DL he has pitched in a variety of settings, but not as the closer.
Isringhausen has a strong preference to close, and he's closing in on 300 career saves. He currently has 292.
"This is what I've done for a long time," he said. "Now, it's about me going out and doing it. I don't want to go too far beyond that."
Duncan believes that Isringhausen's recent outings have shown that he's at least close to regaining his old form. That, combined with a recent slide by Franklin, prompted the Cards to make the change. Both pitchers were notified prior to Monday night's game against Atlanta.
Matthew Leach is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.