Teen phenom Bryce Harper fouled a ball off his left ankle trying to lay down a bunt against Ben Sheets in the first inning of the Washington Nationals' afternoon game of a double-header against the Atlanta Braves. Two innings later, Harper was removed from the game, according to the Washington Post, and replaced by Roger Bernadina. If the injury is serious, it could spell trouble for the first-place Nats, for whom Harper is a major source of energy. From the Post's Adam Kilgore:

The severity of the injury is not yet known. It could test the Nationals' thin outfield. [...]

The Nationals designated veteran outfielders Rick Ankiel and Xavier Nady for assignment over the past three days. If the Nationals needed another outfielder, they would turn to Corey Brown, who is hitting .302 with 21 home runs for Class AAA Syracuse and joined them briefly earlier this year. When the Nationals cut ties with Ankiel, Manager Davey Johnson cited Brown's presence as a reason for the move.

Nats announce Harper's removal was "precautionary." Injury called a "sore left ankle." So that sounds like best-case.

— Adam Kilgore (@AdamKilgoreWP) July 21, 2012

Harper has struggled recently after a red-hot start, with no home runs in his last 75 at bats and just 17 hits in that timeframe. His season line is now .268/.339/.440 with eight homers and 26 RBI in 72 games.

For updates on Harper and the Nats, check out Federal Baseball and SB Nation DC.