OK, let me preface this by saying this is pure speculation on my part but hear me out - it makes sense.
With word breaking that A-Roid could possibly miss up to four months of the regular season with a cyst and torn labrum in his hip, the New York Yankees could very well be calling up Dayton Moore in the coming days to inquire on the availability of Mark Teahen, a former third baseman.
Yankees GM Brian Cashman told reporters today that the thought of seeking a replacement "hasn't yet crossed into my mind". Well, it will soon cross his mind.
He said they are approaching Rodriguez's situation on a "day-to-day, week-to-week, month-to-month" basis. Still, the Yankees really do not have any options in their system that make as much sense as Teahen would at third. Most free agent third baseman that could make any sort of impact have already signed on with new clubs this offseason*.
*I bet Nomar Garciaparra is wishing he would have held off a couple of days before signing with the Athletics.
There is speculation behind the scenes that they could zero in on Scott Rolen as well as some other veteran infielders that could be plugged in at that position. Still, Teahen is probably the best option for the Yankees. He has hit well over his career playing third, but the Royals aren't necessarily looking to deal him right now. He likely won't be a starter in Kansas City (barring an unforseen injury) so they certainly WOULD deal him with the right offer.
Another consideration is what the Yankees would be willing to give up in any trade for a guy who would essentially be a two-to-four-month rental as a starting third baseman, before shifting into a super-utility role. It's old news that their minor league organization is about as depleted as Kansas City's, but they could be willing to shake loose a prospect or two if they start to feel the Rays and Red Sox breathing down their neck.
Certainly, Teahen isn't their only option - they could go a million different ways with this - but he's probably the best one right now.