The Nationals slugging first baseball has been known as one of the biggest defensive liabilities in baseball throughout this career (mostly as a left fielder), but it appears that Dunn is making a strong effort to make himself a quality first baseman. Take it away, Mark Zuckerman:
Adam Dunn has been doing extensive defensive work at first base the last week with Tim Foli and Pat Listach. Listening to Dunn talk about it today, it's clear he's committed to making serious strides at a position he had only minimal experience at prior to last summer. "This is definitely a fresh start for me," he said. "I'm really having to learn a new position for me. I know I've played it before, but I never learned it. Now, as far as my footwork and things like that, it's learning a new position. That's exciting, and it's been fun so far."
If Dunn can prove himself to be an adequate first baseman this season, then he will make himself much more valuable on the free agent market. Dunn, who is scheduled to be a free agent after the season, will be much less of a liability for interested teams.
Right now, the limitations of Adam Dunn (defense, speed, batting average) would make it difficult for teams to commit to Dunn long term despite his immense gifts (power, ability to get on base).
On a side note, there have been murmurs that the Nationals want to extend Dunn, which might be the best option given how many quality first basemen are set to hit the market this winter (Lee, Konerko, Pena, Overbay). It's difficult to predict what kind of money will be thrown Dunn's way nine months from now or even before, but he might not be able to do better than a two or three-year deal.