The Nationals placed left-handed pitcher Felipe Rivero on the 15-day disabled list with a gastrointestinal bleed, the team announced. The move is retroactive to April 18.
With an extra spot on the 25-man roster, the Nationals recalled right-handed pitcher Matt Grace from Triple-A and he is available to pitch in Wednesday's game against the Cardinals. Grace, 23, failed to make the team out of spring training.
The Nationals are the favorites (-101) over the Cardinals on Wednesday.