The benches and bullpens clear after Desmond objects to a high and inside pitch in the fourth inning of a 6-0 game.
Stephen Strasburg vs. Tom Koehler.
Leon has started four of the past six games, including back-to-back ones, over Lobaton.
The outfielder said he feels even better than Monday and hopes to be ready to return by Saturday.
The two outfielders are dealing with minor injuries. Harper has a tight left quad and McLouth had a sore left knee.
The third baseman visited a specialist in Cleveland on Monday.
The outfielder is playing despite leaving Monday's game in the seventh inning with a tight left quad.
Tyler Clippard added a splitter, in part, because of how he lost the Nationals closer's job in 2012.
Through 13 games, the Nationals have outscored opponents 33-14 from the seventh inning on.
The Nationals have committed 13 errors in 13 games, more than half in the weekend series in Atlanta.