In the case of Matt Garza, [xFIP] tells us something far more encouraging, with a better team around him, he could be an ace. I don't mean just the ace of the Cubs, he's already that. I'm talking about ace in the truest sense of the word -- a guy who can go out every 5th day, put his team on his back, and dominate the opposition...Since coming to the Chicago Cubs, Matt Garza has moved in the best of all directions: He has increased his strikeouts, reduced his walks, and wrangled his home runs under control (all with respect to his career rates).
If the Cubs had a better team we could have been talking about Garza as one of the top pitchers in baseball, perhaps even a Cy Young candidate.
I have often and loudly protested the Matt Garza trade, buy never because I thought Matt Garza was below average — no, no — only because his timeline did not fit with the Cubs timeline (he's peaking, they're rebuilding).
That said, pitchers age differently than hitters and, if he can continue at this level, he could play a key role in helping the Cubs bounce back in a year or two. Read the Cubs Den article above by John Arguello if you doubt Matt Garza's filthiness.
He really has been marvelous this season, and it would be awesome if the Cubs can put a quality team around him sometime soon.