Graves spokesman John Donnelly said the north Georgia congressman was trying to beat Kansas Rep. Tim Huelskamp to the hoop at a Washington gym on Wednesday night. Graves jumped up, came down and hurt his left ankle.
Huelskamp said in a statement that he stole the ball from Graves, who did not score.
Donnelly said an X-ray showed that Graves suffered a broken ankle. More tests may be needed once the swelling in Graves' foot recedes to determine if he suffered other injuries.
Graves has cleared his schedule for several days so he can rest at his home in Ranger. Donnelly said the Republican lawmaker will not miss any votes.