Johnson was the first player to appear in a game for all five American League East teams;[1] Steve Pearce became the second in 2018.

Johnson decided to forego a scholarship offer to play college baseball at Texas A&M in favor of signing with the Braves.

He was placed on the disabled list during spring training after experiencing pain while making throws from the outfield, and had Tommy John surgery performed by Dr. James Andrews on June 1.

In the 48 games Johnson played in May and June, his on-base percentage was .325, well below the acceptable rate for a good leadoff hitter.

With Escobar taking over full-time at shortstop, Johnson began the year as the Braves second baseman for the 2008 season.

[8] Johnson ended the 2008 season with a .287 batting average, 12 homers, 69 RBIs, 86 runs, and 11 stolen bases.

Johnson hit a solo home run in the first, a ground-rule double in the fifth, a two-run triple in the sixth and completed it with a single in the eighth.

On July 8, 2011, Johnson hit his second grand slam in the season off St. Louis Cardinals pitcher Kyle Lohse.

On August 23, 2011, Johnson was traded to the Toronto Blue Jays in exchange for second baseman Aaron Hill and shortstop John McDonald.

[14] Johnson was set to debut for the Blue Jays on August 24, but had to return to Arizona because he forgot his passport.

Johnson got 50 starts in left field (the most on the team), splitting time with Matt Joyce and Sean Rodriguez.

The Red Sox traded Johnson to the Baltimore Orioles, along with Michael Almanzar, for Ivan De Jesus Jr. and Jemile Weeks on August 30, 2014.

On July 24, 2015, the Braves traded Johnson and third baseman Juan Uribe, along with cash considerations, to the New York Mets for minor-league pitchers John Gant and Rob Whalen.

In his first game as a Met, he hit a single, a double, and a home run in a 15–2 victory against the Los Angeles Dodgers.

[34] In the summer of 2018, Johnson was among the former MLB players who appeared with the Louisville Stars, a tournament team at the Bluegrass World Series.