Infielder Brooks Conrad was promoted from Triple-A Gwinnett to take Johnson's roster spot. Conrad hit .259 with nine homers and a .769 OPS (on-base percentage plus slugging percentage) in 73 games for Gwinnett.
In his last Minor League game, Conrad was about to lead off the seventh inning when his coach told him, "You're not going to hit; you're going to the big leagues."
Conrad made the Triple-A All-Star team the same day as his promotion, but he won't be able to play in the All-Star Game, scheduled to take place on July 15, now that he's with the Braves.
Conrad, who arrived in Washington on Friday morning, made his Major League debut with the A's last year. During a six-game stint in the Majors, he recorded three hits, including a double, in 19 at-bats.
"It was such a short stint last time," said Conrad, who was acquired by the Braves as a six-year free agent last offseason. "The second time is just as exciting for sure.
"It was definitely my goal to come back up here. You never know if your goals are going to come true. This one did and it's a great feeling."
After Martin Prado produced a four-hit, four-RBI performance during Tuesday night's 5-4 win over the Phillies, he learned that he had earned the opportunity to serve as the Braves' everyday second baseman. Prado had spent most of the previous month platooning with Johnson.
Johnson, who has hit .198 with three homers and a .590 OPS in his past 63 games, began this season as Atlanta's everyday second baseman and leadoff hitter.
Manager Bobby Cox said Johnson was slated to receive a shot in his wrist on Friday, rest three to four days and then start the rehabilitation process to see how it responds.
While Prado will continue to be the everyday second baseman, Conrad will provide the Braves' bench with right-handed power potential. He combined for 95 homers while spending the past four seasons at the Triple-A level with the Astros and A's.
Mark Bowman is a reporter for MLB.com. Mark Selig, an associate reporter for MLB.com, contributed to this report. This story was not subject to the approval of Major League Baseball or its clubs.