Nationals second baseman Daniel Murphy had knee surgery in October and has yet to play in a major league game this season.
Catcher Matt Wieters went on the disabled list April 2 and outfielder Adam Eaton followed nine days later. Starting pitcher A.J. Cole made just two starts before veteran Jeremy Hellickson was slated to take his spot in the rotation Monday night in New York, when the slumping Nationals were set to begin a three-game series against the division-leading Mets.
The major league season is less than a month old and the organizational depth of the Nationals is already being tested.