Outside of there being 162 games played per team between March and early October, the baseball season offers few guarantees. The Yankees will probably be good, the Orioles will probably be bad, and Roy Halladay will probably be a Cy Young candidate, but these are only probabilities, not certainties. On the other hand, there is one thing that is still a guarantee, because for all our advances in western medicine, playing a physical game will always involve physical risks. Thus, there will be injuries.
Some players get hurt so much they acquire reputations for being made of glass (here's looking at you, Nick Johnson), while others remain largely injury-free throughout their career (take a bow, Robinson Cano). Some injuries will utterly decimate a team (Buster Posey wasn't the only Giant to hit the DL last year, but his absence arguably hurt the team the most), while others might almost seem to benefit the team (if Xavier Nady never hurts his arm, does Nick Swisher become the Yankees' right fielder?) Then, of course, there are those injuries that occur as a fluke (Joel Zumaya and Guitar Hero, for one), and turn out to be incredibly problematic.
Which brings me to David Robertson.
Robertson got hurt Wednesday evening after stumbling down stairs, and while most of us have probably missed a step or two in our lifetimes (okay, okay, so I'm a klutz...), most of us are also not professional baseball players. The details of the injury are still not entirely known; what is known is that Robertson hurt his push-off foot and that the MRI he underwent showed some reason to be concerned, so he will undergo additional tests.
Now, Joba Chamberlain aside, middle relievers are not supposed to be the most important players on a team. They are, to a point, supposed to be a dime a dozen, interchangeable, like the type of auto parts you can pick up at your local Wal Mart as opposed to having to leave your car with the mechanic. Unfortunately, this metaphor does not give any weight to just how important Robertson was to the Yankees last season. After Chamberlain and Rafael Soriano were both hurt early in the season, Robertson was forced into the eighth-inning role, and performed so well that even when Soriano returned healthy, Robertson kept his spot.
Robertson's statistics last season were so good (including an ERA just a tick over 1.00) as to land him Cy Young votes; his numbers in high leverage situations and with the bases loaded (just one hit allowed in 19 such at-bats) were so good as to almost become something of legend—at the very least, good enough to earn him the Houdini nickname. It is highly unlikely that Robertson would have been able to repeat such a feat in 2012, but that has more to do with an unsustainably lucky 2011 than it does any substantial regression on the pitcher's part. In English, even a not-quite-as-good Robertson in 2012 is still incredibly important to a Yankees' team that, throughout the entirety of Joe Girardi's managerial tenure, has placed significant emphasis on the success of the bullpen.
Since, as of Thursday evening, we don't know the full extent of Robertson's injury, we don't know how much time he will miss. What fans will remember, however, is the last time a Yankees' pitcher injured his push-off foot, it set in motion a chain of events that nearly ended his career. No, a foot injury is not as instantly devastating as a shoulder one, but a rushed rehab that results in altered mechanics can have devastating consequences. We don't know, yet, if Robertson's injury is as severe as Wang's, but no matter the extent, the Yankees can't afford to rush him back.
If it turns out that Robertson's injury means he will miss extended time into the season, the Yankees will need Soriano to be much more effective than he was in his limited action last season; Chamberlain, recovering from Tommy John surgery is slated for a mid-season return at earliest. This could in turn add another dimension to the presumed battled between Freddy Garcia and Phil Hughes for the fifth start slot; while it's an expectation that the loser of that battle will wind up in the bullpen, Hughes' prior pen experience (and eighth-inning experience at that) suddenly becomes that much more important.
The hallmark of a Joe Girardi Yankees team over the past four (going on five) seasons is a bullpen that, for all its questions and uncertainties at the beginning of the year, usually ends up as one of the best in the league. The Yankees' bullpen would take a huge hit without Robertson, but the team is not without other resources. Thus, the Bombers remain best served by allowing Robertson to fully heal, even as they will hope that the injury is not as serious as feared.