The Cardinals have traded reliever Chris Perez and a PTBNL for outfielder Mark DeRosa. DeRosa will probably play 3B for the Cardinals for now. This deal is a shot to the Cubs who were rumored to be looking at DeRosa earlier last week, but more importantly, gives the Cardinals a very good and versatile hitter who can play OF or 3B or 2B.
I wouldn't be surprised to see the Cardinals deal for another outfielder as they have been rumored to be in on A's outfielder Matt Holliday. I don't see DeRosa as the bat needed to protect Albert Pujols, but this move definitely strengthens their lineup. This deal almost certainly means they cannot count on Troy Glaus to return this year.