He played in Major League Baseball (MLB) for the Oakland Athletics, Washington Nationals, Milwaukee Brewers and Chicago White Sox.

A two-time All-Star, González led the National League in wins and won the Warren Spahn Award in 2012.

González was born in Hialeah, Florida, to a Cuban immigrant mother from Havana and a first-generation Cuban-American father from New Jersey.

After his junior year, he transferred over to Monsignor Edward Pace High School in 2004 where he played with future Nationals teammate Chris Marrero.

On January 3, 2008, the White Sox traded González along with fellow prospects Ryan Sweeney and Fautino de los Santos to the Oakland Athletics for Nick Swisher.

On December 23, 2011, the Athletics traded González and Robert Gilliam to the Washington Nationals for Brad Peacock, Tommy Milone, Derek Norris and A. J.

[13] When González and the Nationals beat the Milwaukee Brewers on September 22, it moved his record to 20–8 and he became the first pitcher in MLB to reach the 20-win mark on the season.

[16] González's name, along with those of other MLB players, was listed in connection with a clinic thought to produce performance-enhancing drugs in a January 2013 report.

[19] In 2015, he was 11–8 with a 3.79 ERA and led the major leagues in allowing opposing batters the highest batting average on balls in play (.341).

In a 2–1 loss of Game 4 of the NLCS against the Los Angeles Dodgers, Gonzalez suffered a high ankle sprain, attempting to field a ball hit by Yasiel Puig, ending his season and being replaced by Zach Davies on the Brewers roster.

On December 20, 2019, González signed a one-year, $5 million contract with the Chicago White Sox, with an option for 2021.

[30] With the 2020 Chicago White Sox, González appeared in 12 games, compiling a 1–2 record with 4.83 ERA and 34 strikeouts in 31+2⁄3 innings pitched.

On March 3, 2021, González signed a minor league contract with the Miami Marlins organization that included an invitation to spring training.

[32] He announced his retirement on March 25, 2021, stating that donning the jersey of his hometown club was one of his "biggest dreams" but that his "body wasn't keeping up with his mind.

González's pitches had above-average strike out whiff rates, with the curveball leading at 36% and the changeup close behind at 35%.

In 2012, González created the GIO (Giving Individuals Opportunities) foundation, a charity to assist medical patients in need of financial support.

[37] On July 13, 2024, González returned to Nationals Park in a guest pitching appearance for the Savannah Bananas, throwing a perfect inning.