Why?? Because the Wednesday deadline was an arbitrary one, set by Pujols. The team was under no legal obligation to settle at that time.
Think about it. Why would the Cardinals make such a ridiculous statement like that?? What would the effect be on Pujols, his teammates, and the fans, knowing that he's in a lame-duck year.
This is where your simple logic is incorrect. There is a tactic, commonly used in business, called negotiation. Negotiation is defined as "the bargaining (give and take) process between two or more parties (each with its own aims, needs, and viewpoints) seeking to discover a common ground and reach an agreement to settle a matter of mutual concern or resolve a conflict."
This is what the Cardinals are attempting to do, but the process was made public because of this artificial deadline imposed by Pujols. There will be a window of time after the season for the two sides to negotiate further.