First of all, if you're going to have an injury that needs rest and time, it's far better to have it in February than in April. The sky is not falling. But...there are increasing clouds on the horizon, and the storm has yet to reveal whether it might pass through Oakland. Spring training is all about "what-ifs" anyway, so what-if...our dear SS is out of commission for a significant number of games again this year--whether due to his current rotator-cuff owie, or the injury (next-body-part-on-the-list-itis) we all worry about him sustaining when he actually plays.
First of all, let me disagree with two extremes I have seen expressed so far on AN. Crosby, as a dangerous hitter playing at a key defensive position, is integral enough to the A's that his loss would impact Oakland far more than to the tune of one loss every 20-30 games; and in any event, a rate of 5-6 losses per season can easily make the difference in a division-title quest. However, with the additions of Thomas and Bradley (sorry, I can't recall either of their last names at the moment), the 2006 team has far more offensive depth than before, and Crosby's absence should not cause the A's to plummet out of contention to where Zito would be dealt as a concession to the 2006 season.
The 2006 A's have enough offense and enough defense at shortstop to tread water just fine for a while without Crosby--but unfortunately the offense and defense don't reside with the same player. Antonio Perez is probably a very acceptable offensive substitute. Remember, many teams don't have "heavy hitting" shortstops, and pre-Cal Ripken, a team was happy to get 10 HRs out of its .260 hitting shortstop. The A's only missed Crosby so much last year because they didn't have much of a supporting cast; Perez could easily slide in and be a very decent offensive SS in the American League, with less power, but a better OBP, than Croz. But what a defensive dropoff at such an important position. And Marco Scutaro is plenty decent at SS for a "Plan B" fill in, but the A's have 3-4 hitters whose batting average could easily match Scutaro's career OBP of .303 (eeww).
So would losing Crosby for an extended period of time inspire the A's to make a move to acquire a superior substitute? I doubt it. Adequate shortstops are not found riding the pines of major league rosters everywhere, and to acquire a worthy replacement (Julio Lugo, by the way, has a career OPS of .739), the A's would have to be willing to weaken themselves too much elsewhere.
So what to do, what to do, in this hypothetical nightmare? Sans Crosby, I think the A's would huddle to decide whether they feel they can better afford to sacrifice offense or defense at SS. The outcome of that huddle would determine who, among Perez and Scutaro, got 75% of the starts, and who was used to sneak in as many ABs, or as many defensive innings, as possible. (Remember when the A's had Rob Picciolo and Chicken Stanley, and on the road Billy Martin would start Picciolo leading off, get him one at-bat, and then insert Stanley for defense in the bottom of the 1st inning? No, you don't remember that? You're lucky.)
Indeed, a Perez/Scutaro replacement wouldn't be comparable to Crosby by any stretch of the imagination. But with the A's 2006 starting rotation and supporting cast, it wouldn't be time to wave the white flag any more than it would be time to raise the "2006 division champions" flag. What it would be time to do is to take a hard look at how the A's can enter the 2007-2009 seasons with more than potential greatness on the left side of the infield. Potential Greatness is a truly swell guy, but look at his hands sometime. You won't see any rings.