Tottenham Hotspur were beaten 2-1 by Arsenal on Wednesday night in the Capital One Cup.
Neither Wimmer nor Fazio covered themselves in glory with their performance, and Redknapp felt that Pochettino was wrong to select them both.
"I think Pochettino made a bad decision by playing Wimmer and Fazio together," he said. "They were all over the place, especially for the first goal.
"The two centre-backs were the key, for me. It just didn't make any sense. Change one or the other. The centre-backs do the least amount of running. If you've got something solid, keep that going. Why would you change it?"
So far this season, Pochettino has generally selected Toby Alderweireld and Jan Vertonghen as his first choice pairing in the centre of the defence, and they have looked secure.
However, a Mathieu Flamini double meant that the Gunners left White Hart Lane celebrating, and killed the momentum that Spurs had built up.
Tottenham's next game comes against Manchester City in the top-flight on Saturday, where Pochettino is likely to restore both Alderweireld and Vertonghen to his starting line-up.