Perez, ranked No. 7 among the team's top prospects, was promoted to the big leagues this past Saturday after Werth was placed on the DL because of a hamstring injury.
Entering Tuesday's action, Perez has appeared in two games and has been hitless in one at-bat. Before the promotion, Perez was having a great year for Syracuse, where he was hitting .346 with six RBI and seven stolen bases.
Bill Ladson is a reporter for MLB.com and writes an MLBlog, All Nats All the time. He also can be found on Twitter @WashingNats. Andrew Simon is a reporter for MLB.com. Follow him on Twitter @HitTheCutoff. This story was not subject to the approval of Major League Baseball or its clubs.