If Zack Greinke doesn't re-sign with the Angels, they'll have lost three-fifths of their starting rotation, with no top-shelf replacements in sight.
Hunter's coming off an excellent season, and this is probably a good time to mention that he has aged exceptionally well, with a significantly better OPS+ from ages 32-36 than 27-31. That's no mean feat. Still, it's hard to argue with a team's decision to not commit a great deal of money to Hunter, considering that he did turn 37 last July. It's highly likely that we've seen his best, but whoever signs him for the next three or four years will probably be paying for his best (without getting it).
It's also hard to argue with the Angels trading Ervin Santana to the Royals, and not picking up their big-money option on Dan Haren; general manager Jerry Dipoto and his staff presumably know a lot more about Santana and Haren than we do.
They also know a lot more than we do about their chances of re-signing Zack Greinke. As things stand now, though, here's the Angels' 2013 pitching rotation:
Only eight pitchers started even one game for the Angels last season. Weaver, Wilson, Haren, Santana and Greinke accounted for 137 of 162 starts. Journeyman Jerome Williams started 15 games, and went 6-8 with a 4.83 ERA. Rookie Garrett Richards started nine games, and went 3-2 with a terrible strikeout-to-walk ratio. Brad Mills started once.
Richards was considered the Angels' top pitching prospect, but his performance in Triple-A was uninspiring. Mills pitched poorly in the minors last season. The number of MLB-ready, starting-pitcher prospects in the Angels' farm system is approximately zero.
Now, here's the Angels' projected outfield without Torii Hunter:
In the middle, Mike Trout can do literally everything. In left field, Trumbo can hit but can't run or field. In right, Wells can't hit or run or field. There's also Peter Bourjos, who has been wildly inconsistent as a hitter in the majors. While a natural center fielder, Bourjos would at least give the Angels fantastic defense in one of the corner spots.
And again, no help coming from the minors. Well, except for maybe 5'10", 200-pound Kole Calhoun, who posted solid numbers in Triple-A this year after completely skipping Double-A. He's no Torii Hunter, though. Not yet, anyway.
We can be sure that Jerry Dipoto, nobody's fool, has plans for improving the club. Or at least keeping them on the beam; after all, they did win 89 games this season, and would have won more if Mike Trout and (the real) Albert Pujols had been around in April. But Dipoto's options are narrowing quickly. He doesn't have much trade bait because the farm system is relative bare. And if Greinke and Hunter escape, the Angels' options on the free-agent market will be quite limited, as this year's crop is probably the weakest in many years.
And the scary thing is that even if Greinke's back, the Angels will still have two rotation slots to fill, which will be either silly-expensive or probably ineffective.
It's far too early to count out the Angels in 2013. But they've got a lot of work to do between now and Opening Day.
Update: According to this piece, Dipoto and (presumably) Mike Scioscia have already decided that Mike Trout will shift to left field -- a waste of talent, in this writer's opinion -- with Bourjos taking over in center field, and Trumbo playing right. This does not materially change the basic equation, which is that the Angels will have one outstanding outfielder, and two decent ones.