During the bulk of the 2012 season, the Nationals carried three left-handed relievers in their bullpen. For the final month of the season, they had four southpaws working in relief.
As of today, the Nats don't have a single lefty reliever under contract for 2013.
Sean Burnett, Michael Gonzalez and Zach Duke are all free agents this offseason, and will test the market before determining where they land for next year. Tom Gorzelanny is entering his final arbitration year, and while the Nationals control his rights and can bring him back by tendering him a contract, there's no guarantee they'll do so.
While the Nats are trying to figure out what will happen with free agent first baseman Adam LaRoche and monitoring the market for a free agent starter, they also will have to determine which relievers to bring back for next year.
Strangely enough, the Nationals will return all of their right-handed relievers from last season. Drew Storen, Tyler Clippard, Ryan Mattheus, Craig Stammen, Henry Rodriguez and Christian Garcia will all be back going into spring training, although Garcia might be converted to a starter.
The lefties, however, are a question mark.
Burnett will be the toughest guy for the Nationals to bring back. The 30-year-old battled through elbow discomfort to put up a 2.38 ERA this season, and he'll probably be the most sought-after left-handed set-up guy on the free agent market.
The Nats have a shot to sign Burnett, but it would probably take a three-year deal worth $12-15 million.
Gonzalez was one of the least-heralded additions to the Nationals' roster this season, but he was a major factor both on the mound, pitching to a 3.03 ERA, and in the clubhouse, where he mentored a number of the Nats' younger players. Gonzalez would like to return to the Nats and wouldn't demand nearly as large a contract as Burnett, so he's definitely a guy the Nats will be in touch with.
That leaves Duke and Gorzelanny. Duke signed a minor league deal with the Nats during the spring and spent most of the year in the rotation at Triple-A Syracuse, putting up strong numbers. He then joined the Nats after rosters expanded, and fared pretty well in relief, allowing just two runs in 13 2/3 innings. Gorzelanny played a vital role in 2012, eating innings out of the 'pen as the Nationals' left-handed long-reliever and posting a 2.88 ERA.
Gorzelanny is likely due to make around the $3 million that he earned last season, which is a lot for a reliever who mostly pitches prior to the seventh inning. The Nats like the job he did, however, and might be willing to keep him for next season. If not, Duke could be a candidate to replace Gorzelanny as the lefty long man.
Burnett is the real wild card here. It will take a decent sized contract to retain him, and the Nats might not be able to match the offers the southpaw gets on the open market. They'd love to bring Burnett back, but if that's not an option, Jeremy Affeldt is another guy to watch. The 32-year-old, who was with the Giants the last four seasons, will also land a nice contract, though he might be a bit cheaper than Burnett.
Regardless of who it is, the Nats will need to find a lefty that they can trust to work late in games. Gonzalez is more of a matchup lefty, but Burnett excelled at getting both right- and left-handers out. If he leaves via free agency, the Nats will have a pretty good hole to fill at the back of their bullpen.