Interesting trade made by the Cubs today, sending 5 players to Tampa while getting three players back themselves, including Garza. This should be a good move for him fantasy (and career)-wise. Getting out of the AL East will do wonders for his value. In his small sample against the National League (4 career starts), Garza is 2-2 in 4 starts with 23 IP and a 1.22 WHIP. His ERA is pretty close to 5 but that is because he got shelled in one appearance against the Marlins. I think he will do very well in the NL Central and will benefit from not having to pitch to DH.
My advice: keep an eye on him during the spring. He may be a guy you will pick up in a bigger trade.