The Nationals reinstated Hudson (elbow) from the 10-day injured list Wednesday.
Hudson, who was placed on the IL on June 12 with right elbow inflammation, returns to reinforce the Nationals' injury-plagued relief corps. Before the injury, the righty posted a 2.59 ERA, struck out 35 batters and recorded 12 holds in 24.1 innings. Andres Machado was optioned to Triple-A Rochester in a corresponding move.