Memphis is a weeeeeird baseball town. There are connections to the Cardinals, Braves, Cubs, Royals, Mets and even the Expos. So here's how it works out:
Baseball fandom is pretty much split three ways in Memphis between the three teams in closest proximity, the Cardinals, Cubs, and Braves. Cable TV has allowed the Braves and Cubs (due to Fox Sports South, TBS, and WGN) to attain some dominance, while the highly successful Memphis Redbirds AAA minor-league franchise, an affiliate of the Cardinals since 1997, has definitely increased the number of Cards supporters in the area. The situation is slightly complicated by the fact that the former owner of the Royals, Avron B. Fogelman, is a Memphian, and the previous incarnations of Memphis' minor-league team have been affiliated with the Mets, Expos, and Royals.
But basketball is far more important in Memphis anyway. The Grizzlies have certainly made their mark there, and University of Memphis (formerly Memphis State) Tigers basketball is still the city's second religion.