The "window is closed" on the idea of the St. Louis Cardinals signing a free-agent shortstop, according to GM John Mozeliak. Joe Strauss of the St. Louis Post-Dispatch writes that if the team needs to add a fallback option for the rehabbing Brendan Ryan, they'll explore the trade market rather than signing a free agent.
Given the lack of shortstops left available on the free agent market, we can assume that the GM's comments refer primarily to the team's interest in Felipe Lopez. Last we heard, the Cardinals were one of a handful of teams interested in the infielder, but Mozeliak's comments suggest that the club isn't likely to bring Lopez back to St. Louis. In 43 games for the Cardinals in 2008, Lopez hit a scorching .385/.426/.538.
Mozeliak added that the club should know more about Ryan's health by "the first or second week of March when he truly tests some things." We know that the Cards have a little money to spare, but it sounds like they might wait for more details on Ryan's recovery before deciding how to spend it.