There's no denying Garza has been slightly above average over the last three seasons, despite dealing with some injury issues and not throwing 200 innings or more since 2010. FanGraphs pegged Garza's WAR as 2.2 this past season, just 1.1 the season prior and 4.9 in his last mostly healthy season in 2011. The Twins starters, of course, were likely below replacement level over the last few seasons, so Garza's addition would likely increase the team's wins by even more than his WAR suggests. If the Twins were close to contending and needed to shore up their rotation to get past the Yankees in the playoffs (circa 2004), signing Garza would make a lot of sense.
Twins fans likely don't want to hear about money issues being a reason the team shouldn't target a big name, but with Garza it's the truth. He seems likely to sign a 4 or even 5 year deal, and while early projections of $20MM seem far too high, 5 years and $75MM seems within reach. Paying $15 million a year for five years for a pitcher who will turn 30-years-old before the beginning of next season is a huge commitment for a team like Minnesota. Once his health concerns are considered as well, the reward doesn't seem to outweigh the risk.
At $15MM a year, Garza would need to average a WAR of 3.0 per season each year of his contract to earn his money. He failed to reach that benchmark in each of the last two seasons, and while an increase in innings would help his WAR considerably, expecting more than 170 innings out of Garza would be silly.
I'm not sold on the idea that he will struggle in the AL, as some suggest, because he struggled in a few starts with Texas after being traded. The sample size was simply far too small to gather any real conclusions about that. My best guess is that over the next five seasons Garza will have just one season in which he throws over 200 innings, and that will also be the only season that he earns his salary. Pitchers with a history of arm issues don't tend to pitch well into their mid 30's. For a team like Minnesota who is likely not going to contend in 2014 regardless, it makes no sense to spend big money for a long time on a starter who is already showing signs of declining. If Josh Johnson signs a one year deal to try to get back to his old self, the Twins would be foolish not to target him. Despite Garza's better pitching over the last two seasons, Johnson would require far less of a commitment, which is very important to a rebuilding team. If Garza gets hurt again and his skills fall off considerably, the Twins will have wasted more than 15% of their payroll on a pitcher who was never likely to be more than a #3 starter by the time the team is ready to contend anyway.
It's definitely nice to see the Twins targeting some big name pitchers, and as frustrating as their starters have been to watch over the last few years, the need is clear. I'd just prefer the team wait for a better crop of free agent starters to go on a spending spree, or that they at least wait until they're closer to contention to target a 30-year-old injury riddled starter. As a Twins fan, we've seen countless players leave over the years because we simply couldn't afford them; here's to hoping Matt Garza stays a former Twin because his demands are, as always, too high for the Twins.