The Nationals are still seriously pursuing free-agent first baseman Prince Fielder, according to an unidentified source. The source added that the most likely suitors for Fielder are the Nationals, Rangers and Marlins, and that the Cubs and Mariners, widely rumored to be interested in Fielder, aren't serious contenders at this point. The biggest sticking point in negotiations between Fielder and the Nationals is the length of the contract.