(Al Behrman/AP)

Mattheus has been pitching with soreness in his foot for about two weeks, he said, and he aggravated the injury Monday afternoon while jogging in the outfield. Mattheus underwent an X-ray Monday evening, which was negative.

Mattheus allowed two hits and a walk but no runs in one inning yesterday. For the season, Mattheus has a 2.25 ERA and 13 strikeouts with seven walks in 20 innings. With Henry Rodriguez no longer the Nationals’ clear-cut closer, Mattheus could be one of the candidates to get the ball in the ninth inning.