It was the first time Cordero was on the mound since the end of Spring Training.
Cordero threw all fastballs during the session. He will have another bullpen session on Monday at Nationals Park.
"Everything felt fine," Cordero said. "From the windup, everything was good. From the stretch, it was even better."
Cordero hopes to come off the disabled list on Friday.
Meanwhile, first baseman Dmitri Young had a cortisone shot in his back on Saturday. He hopes to be ready to play by Monday, when the Nationals face the Marlins.
Young has been bothered by tightness in his back since Spring Training. He is 1-for-2 with an RBI this season.
Bill Ladson is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.