Bryce Harper was held out of the Washington Nationals' lineup against the Los Angeles Dodgers as a precautionary measure Tuesday night. The outfielder banged his left knee while making a sliding catch in the third inning of the Nationals' 8-3 victory Monday night, but stayed in the game. ''Overnight he had some pretty significant swelling, so we're trying to get that out of there,'' Nationals manager Matt Williams said.