B.J. Upton of the Tampa Bay Rays could be a target as the Nationals shop for center fielders. (Chris O'Meara/Associated Press)

At this time last year, the Washington Nationals shelling out a $126 million contract seemed unthinkable, the image of Jayson Werth wearing a Nationals uniform looked weird and the words “Phase 2” sounded like something out of bad science fiction. And then the Nationals rapidly and radically transformed their reputation, from a last-place franchise that sits on the sideline to a ready-to-spend wild card with deep pockets.

The reverberations are still being felt. Since the Lerner family and General Manager Mike Rizzo proved the Nationals are willing and able to break the bank, and do so unpredictably, the Nationals have found themselves named in speculation as a possible suitor for most every big-name free agent available this offseason.

The Nationals’ activity this offseason, though, may not fit their new image. When free agency begins in earnest Thursday at 12:01 a.m., the Nationals will find themselves in the unfamiliar position of shopping for players that, when added to their current roster, could provide them a realistic chance at contention. The question is, how will they narrow their shopping list?

Rizzo believes the Nationals can reach the playoffs with upgrades in center field and in their starting rotation. The Nationals’ recent history, going back to their $180 million bid for Mark Teixeira in 2008, suggests they should not be counted out of anything. But they also do not feel desperate to add a big-ticket free agent.

Take, for instance, the top two free agents available. Speculation has abounded regarding the Nationals and slugging first basemen Albert Pujols and Prince Fielder. But Rizzo has insisted both publicly and privately that he feels comfortable with the Nationals’ first base situation — with Adam LaRoche coming off shoulder surgery and Michael Morse having proved himself capable — and will look elsewhere to improve the Nationals in free agency. Despite buzz to the contrary, the Nationals are unlikely to seriously pursue Pujols or Fielder.

(However, if Washington did try for one of them, Fielder is a more likely target. His left-handed bat fits better into their lineup, he’s four years younger than Pujols and he’s represented by Scott Boras, the agent with whom the Nationals have shared a fruitful relationship.)

The Nationals are more focused on adding a center fielder who can provide better production at the top of the lineup. The free agent market for that type of player is thin, though it grew over the weekend when the Cleveland Indians declined their 2012 option on oft-injured Grady Sizemore.

To land the center fielder they desire, the Nationals may look to make a trade. Starting pitching is the most valuable commodity in baseball, but the Nationals have enough depth, especially if they can finish up a deal with Chien-Ming Wang, that they feel they can trade pitching for an outfielder. B.J. Upton could be a target, but many expect the Tampa Bay Rays to non-tender Upton, which would make him a free agent.

Last year, the Nationals made acquiring a top starting pitcher their first priority, a goal Rizzo has carried into this offseason. The best starter available is Rangers left-hander C.J. Wilson, a 31-year-old who has a 3.14 ERA over the past two years. Japanese superstar Yu Darvish, 25, is expected to become available via the posting system and would rank just behind or right beside Wilson. The Nationals have scouted them both, and Rizzo called Darvish “a great talent.”

But the Nationals may be more likely in the market for a less-splashy, stabilizing veteran starter, and not just a minor upgrade like Jason Marquis two offseasons ago. Some individuals with ties to the Nationals believe they will pursue Mark Buerhle, 32, a left-hander who has spent all 12 of his major league seasons with the Chicago White Sox.

Their payroll suggests the Nationals will have financial flexibility in free agency. The Nationals entered opening day 2011 with a $68.3 million payroll. The team shed the expiring contract of Marquis, but no other sizeable free agent contracts come off their books, and several current players will see their salary rise through either contractual bumps or arbitration raises. Before they do any winter spending, including estimates for arbitration-eligible players the team is likely to re-sign, the Nationals have roughly $62 million committed to their 2012 payroll.

They have the capacity to spend, but the Nationals may decide they are better off allowing their young roster, with a center fielder added to the mix, to develop without a splashy addition. The free agent search will be affected by several factors — including the development of Bryce Harper in the Arizona Fall League; he could give the Nationals a powerful, left-handed bat if he convinces the Nationals he’s ready.

The Nationals could do any number of things this offseason. Being predictable is probably not one of them.