From the Post-Dispatch, apparently Carpenter threw off the mound today for about 10 minutes with no discomfort.  Article Here

To my mind, that is fantastic news.  Apparently McClellan is pitching on the same days as Carpenter in order to be a seemless backup.  Lets hope that Carp continues to progress normally.  He really means the season for the Cards this year.

The article goes on to state that there is no reason why they will treat Carpenter any differently this Spring than any other pitcher.  I still prefer McClellan to Pinata, so we will have to see how things shake out.