The Nationals optioned Abbott to Triple-A Rochester following Sunday's 9-3 win over the Phillies, Jesse Dougherty of The Washington Post reports.
MLB teams won't be able to carry more than 12 pitchers on the 26-man active roster beginning Monday, so Abbott's demotion will bring the Nationals down to the maximum allotted arms. He made his team debut Sunday, striking out one over a scoreless inning to finish out the game.