In 2005, De Aza batted .286 with 34 stolen bases and 75 runs scored while playing for the Jupiter Hammerheads of the High–A Florida State League.

On March 28, 2007, De Aza was named the starting center fielder for the Marlins, beating out Reggie Abercrombie, Eric Reed, and Alex Sánchez in what was seen as a surprise.

On July 27, 2011, he hit the first home run of his MLB career, off Detroit Tigers pitcher Max Scherzer.

On January 18, 2013, De Aza signed a one-year, $2.075 million deal to avoid arbitration with the White Sox.

De Aza was the starting center fielder once again, and his main backups were Jordan Danks and DeWayne Wise.

On March 31, 2014, De Aza recorded his first career multi-home run game in an Opening Day win over the Minnesota Twins.

On August 30, 2014, De Aza was traded from the White Sox to the Baltimore Orioles in exchange for minor league pitchers Miguel Chalas and Mark Blackmar.

[5] On June 3, 2015, De Aza was traded to the Boston Red Sox in exchange for cash considerations and prospect Joe Gunkel.

[6] On August 31, 2015, De Aza was traded to the San Francisco Giants with cash considerations for minor league pitcher Luis Ysla.

On June 14, 2024, De Aza signed with the Staten Island FerryHawks of the Atlantic League of Professional Baseball.