As a young starting pitcher under team control possibly until 2014, the Cubs feel strongly that they can net a handful of young talent in exchange for him. Pitchers like Mat Latos and Gio Gonzalez brought back four prospects each. Garza was 10-10 last season for a bad Cubs team. He established himself as more of a strikeout pitcher notching 197 Ks in 198 IP. His 3.32 ERA was a career low, despite facing lesser competition in the National League. What showed progress was his control, something that has hurt him in the past. For Tampa Bay in 2009, he hit 11 batters and threw 3 wild pitches; in 2010 he had 7 HBPs and 12 WPs. For the Cubs last year he only hit 3 batters, throwing 6 wild pitches.
The Cubs will get lucky as a team will overpay for Garza. But the important questions that have to be asked are how much of an impact will he have on his new team and will he ever reach the potential he has to be an ace. He won 15 games in 2010 but pitched to a 3.91 ERA. 2011 saw him net a drop in HRs allowed from 25 and 28, respectively, to just 14.
I look at the Red Sox as the favorite to land him. The Cubs are looking for young pitching and Boston has it. Nobody knows the Boston farm system better than Theo Epstein so there is a well known pool of players he has to pull from. I can't see the Yankees ever parting with Dellin Betances and Manny Banualos. If they were, they should have gotten Ubaldo Jiminez. It would make no sense if they gave either or both of them for Garza. Jiminez is the better pitcher. Teams like Toronto, Detroit, and Miami are all interested and out of the three, the Tigers stand the best due to their pitching prospects.
I can't say Garza is a top pitcher yet. I also can't say he won't get there. He will be traded this offseason, but look at this for one second. The most games he has won outside his 15 in 2010 is 11. I understand he has just four full seasons, but his three with Tampa were all with a good team. James Shields, David Price, and Jeff Niemann seemed to excel with that team around them. I think Garza will get there. The funny thing is, many "experts" are under the impression he already is.