In search of a center fielder, the Nationals have talked to the Twins about Denard Span, according to sources. Washington has also famously targeted Tampa Bay's B.J. Upton. If the Twins agree to deal Span to the Nationals, they may be able to fill their needs at shortstop and in the bullpen. The Nationals also are looking at the Cardinals' Colby Rasmus and Astros' Michael Bourn, sources say.