Outfielder Rick Ankiel has been activated from the disabled list.
He fills the vacancy created when first baseman Adam LaRoche was placed on the 15-day disabled list yesterday by the Nationals with a torn labrum in his left shoulder.
There had been some speculation about first baseman Chris Marrero, one of the up-and-coming infielders in the Nationals' system, potentially getting the call.
Jason Benetti, play-by-play announcer for the Chiefs, said that manager Randy Knorr feels Marrero is ready to make the jump to the majors, but the plan they have in place is to keep him in the minor leagues for the duration of the regular season.
Marrero has had a good season for Syracuse, and has played first base exclusively the entire campaign. The 22-year old from Miami, Fla., is batting .350 the last 10 games, including three games with at least three base hits.
Marrero has had a solid overall season, hitting .275 in 43 games, with eight doubles, four homers and 19 RBIs.