The Chicago White Sox will announce tomorrow that they have signed free agent Adam Dunn. The Washington Nationals’ first baseman has made it clear that he does not want to DH, but his signing with the Pale Hose indicates that he is open to the possibility. His signing leaves the Washington Nationals with a void at first base. The current speculation is that the Nationals will now step up their pursuit of Tampa Bay Rays first baseman Carlos Pena, or perhaps D-Back Adam LaRoche. Of course, it’s always possible that the Nats will decide to use Josh Willingham as their first baseman, or perhaps even Michael Morris — no matter how unlikely those two possibilities may now seem. The departure of Dunn brings an end to the Nationals’ front office debate on whether to keep Dunn because of his bat, or to let him walk because of his defensive liabilities. Chicago’s signing of Dunn is not a complete surprise. The White Sox have always been interested in the slugger, and the Nationals and Pale Hose were involved in intense discussions on Dunn prior to this season’s mid-summer trade deadline. Now — with Dunn walking — the Nationals will receive a supplementary first round pick in the first year player draft and Chicago’s 23rd overall pick in next year’s draft. Dunn, it is reliably reported, will sign a deal with Chicago far in excess of anything that he was offered with the Nationals: four years and $56 million. The Nats were reportedly only willing to offer him a three year contract. The signing of either Pena or LaRoche would be a step-up defensively for the Nationals, though Pena hit an anemic .196 for the Rays, while LaRoche (good around the bag, and with a quick glove), hit .261 — with 25 home runs.