Washington Nationals infielder Carter Kieboom to have season-ending Tommy John surgery 7:58 PM ET Associated Press Nationals infielder Carter Kieboom will undergo season-ending Tommy John surgery to address the elbow issue that landed him on the injured list in March, the latest setback for a former top prospect yet to make an impact in Washington. Manager Dave Martinez said Friday that Kieboom will have the surgery May 27. Kieboom has been dealing with a strained flexor mass and sprained ulnar collateral ligament in his throwing elbow. Editor's Picks Martinez said he's hoping Kieboom returns in time for spring training. He noted that position players have shorter recovery periods than pitchers from the ligament-replacement surgery. Kieboom, 24, batted .207 with a .301 on-base percentage, six homers and 20 RBIs in 62 games last season. He played third base last season but also has experience at shortstop.