The St. Louis Cardinals aren't a conventional free agent destination for a name-brand shortstop, inasmuch as they already have one of their own; Rafael Furcal's progress during his injury rehab has been tracked by GM John Mozeliak in unnecessary detail. Their starting second baseman is still in the fold, too, along with a prospect (Kolten Wong) and a postseason hero (Pete Kozma.) But none of that should keep Stephen Drew (or, in trade, Asdrubal Cabrera) from coming over, because these Cardinals are actually uniquely qualified to play host to a new shortstop.
He'll just have to be... flexible. A guy like Stephen Drew would probably start the season at second base, assuming Mozeliak's hosannas about Furcal are to be trusted; Daniel Descalso, the incumbent, is no threat, and better suited to replace Skip Schumaker as the Cardinals' left-handed-hitting utility infielder than to start.
Why should a shortstop agree to come to Busch Stadium and play behind Rafael Furcal, then? Because nobody plays behind Rafael Furcal, exactly--it's more like playing next to him, and waiting for him to miss 20 or 30 games with some malady or another. Anybody who comes to St. Louis to start at second base is also coming to St. Louis to start for a month or so when Furcal can't go.
Asdrubal Cabrera would probably push Furcal to second. But a guy like Stephen Drew, who is already getting calls about joining contenders as a genuine utility infielder, could burnish his utility credentials at Busch Stadium while also starting 150 games across the infield. There are worse fates.