Feliz is known more for his defense than his offense. This is somewhat encouraging, given the Cardinals could certainly use some solid play at the hot corner. But unfortunately, the Cards main problem is still offense, and Feliz does not improve the batting line-up. This season Feliz is hitting a pedestrian .221, with 4 HR and 31 RBI.
I am under the impression that help in any way, shape, or form at 3B could be beneficial; even if it is just defensive help. It is also encouraging that Feliz has some playoff experience with Philadelphia; he was the everyday 3B for the Phillies during their world champion 2008 season, as well as their 2009 season.