Although the injury to Curtis Granderson should not be understated, his loss for potentially the first quarter of the season is not as bad as it seems due to several moves the Yankees will make to help minimize the loss. The first one is obvious and already in motion, as Brett Gardner will replace Granderson in centerfield. Granderson was below average in center. Depending on the quality of the new left fielder, the move may save a run or two over the first forty games.
The new replacement is going to be moved down the lineup, as opposed to the fifth spot that Granderson occupied in the first exhibition game. Moving his replacement down to eighth in the lineup takes about 15 plate appearances away from Granderson's poor-hitting replacement and gives them to better hitters. If you figure Granderson would have had about 160 plate appearances, you have already removed about ten percent from his replacement. This cascading effect will not work quite as well as it did a year ago when the Yankee bullpen replaced Mariano Rivera because the eighth place hitter is still going to get up to the plate four times a game.
A final consideration that does not even require a move on the Yankees part deals with Granderson's ability to hit left-handers. Although he has had some success against lefties in the past, in 240 PA against them last year Granderson hit .218/.304/.458. Granderson's replacement might not be as good, but he should at least be able to duplicate those stats against lefties.
Instead of replacing 160 quality plate appearances, we moved quickly to 145 with a lineup change, and after removing another third of the plate appearances against lefties, we are left with only 96 quality plate appearances lost to the injury. Out of more than 6,000 Yankee plate appearances this year, the injury is far from breaking the season. If that does not cheer you up, keep in mind the Mets starting outfield is projected as Lucas Duda, Kirk Nieuwenhuis and Mike Baxter, and they do not have any injuries.