A look at each as the general managers' meetings wind down and the off-season kicks into gear:
There may be no more fascinating team to watch this winter. After the disappointing end to the 2012 season, there is little doubt that a major roster restructuring is in order.
Here is their list of free agents, almost all of whom won't be back: Josh Hamilton, Mike Napoli, Ryan Dempster, Mike Adams, Koji Uehara, Roy Oswalt, Scott Feldman, Mark Lowe, Yoshinori Tateyama.
It should be quite evident that the Rangers are moving on from Hamilton. Oh, there is a scenario in which he could return, but if anybody steps up at all financially - and you know somebody will if teams such as the Orioles and Mariners already are expressing interest - the Rangers will let Hamilton walk just as they did with C.J. Wilson last winter.
That will leave an outfield of David Murphy, Craig Gentry and Nelson Cruz, meaning a move will be necessary - whether it be either Upton brother (Justin in a trade, B.J. in free agency), Michael Bourn, a veteran corner outfielder type - or even a position switch for Ian Kinsler, whose second-base defense slipped in 2012.
The latter option also would make room for top prospect Jurickson Profar. But so would putting Elvis Andrus in a package for Justin Upton. Mike Olt also would fit a Diamondbacks need, and should be dealt now, while his perceived value is high.
But the potential Rangers-Diamondbacks match is complicated by the latter's need for a starting pitcher, which the former can't afford to deal at this point - although that could change if Zack Grienke or another free agent is signed.
And knowing the Nolan Ryan-Jon Daniels tandem, you can rest assured pitching will be the No. 1 focus - as it should be. While Grienke is the only front-of-the-rotation free-agent candidate, there are a handful of quality No. 3 types, as well as several quality setup men to put in front of Joe Nathan.
Many dominoes could start to fall throughout this market once the Rangers spring into action.
Payroll commitments for 2013 signal strongly that they will remain in win-now mode despite their 2012 fall from NL East grace.
They have about $123.5 million tied up next season in Cliff Lee, Roy Halladay, Ryan Howard, Cole Hamels, Chase Utley, Jonathan Papelbon and Jimmy Rollins, but that leaves a top-heavy roster with current holes in center field, third base, a corner outfield spot and the bullpen.
The temptation will be to spend to fill those holes and take their best shot at winning again in 2013, but that approach is fraught with risk. The free-agent center-fielder market is very deep, but each possibility carries more potential downside as length and financial obligation increases. And we're not even talking Josh Hamilton here, as moving forward, he's better-suited for a corner spot.
What happens for instance, if Bourn gets a six-year deal, and his speed diminishes after year three or four? A deal for a Dexter Fowler or Denard Span is the better way to go fiscally, but pitching will have to go to get either of those possibilities done. And then maybe make a smaller financial risk on a corner outfielder such as Nick Swisher.
The same goes for third base. If they can't trade for Chase Headley - and it's far likelier that the Padres will sign him long-term - the better option may not be a pricier Kevin Youkilis. Rather a cheaper, short-term option, and then counting on Cody Asche to be ready by 2014.
In short, it's a very tricky set of decisions facing general manager Ruben Amaro this winter, and of course, there always is the option of a more-significant makeover attempt that would include sending Lee elsewhere to fill needs and increase payroll flexibility.
Something along those lines will be far more likely in late July 2013 if things don't go well early next season.
Boston Red Sox
Their successes are much further in the past than the two teams above, but they do have the financial ability to rebuild quickly, as attracting free agents shouldn't be a problem.
There is reported interest in Adam LaRoche and Mike Napoli. But there doesn't appear to be a trade match for Justin Upton, as the Diamondbacks want a No. 2-3 veteran starting pitcher, and either a shortstop or third baseman, and dealing Will Middlebrooks probably isn't going to happen.
The Sox also aren't going to part with Jacoby Ellsbury, not with too many other outfield questions. Jason Bay makes some sense, on a small-guaranteed deal, as he did produce in two years in Boston.
But Shin-Soo Choo is the better, longer-term solution, and that's the way GM Ben Cherington - now firmly in control - likely is thinking. Because this is not going to be an overnight fix in Boston.
In fact, along that line, the biggest off-season changes may already have been made. That is to say manager John Farrell, and just-named pitching coach Juan Nieves. The latter quietly has built a very solid resume, most recently as bullpen coach under Don Cooper with the White Sox.
Nothing will turn around the Red Sox faster than an improved rotation, and there is plenty of room for it coming off their 5.19 rotation ERA in 2012. Nieves could turn out to be a very important figure around Fenway, where they went through three pitching coaches during Farrell's stay in Toronto.
Better sooner than later, the GM-manager-coaches-players merry-go-round has to come to a stop in Boston, and be replaced by stability and a sound organization-building philosophy.