Watson first reached the major leagues with the Pittsburgh Pirates in 2011. After three years, his best came in 2014, where he held a 10-2 record with a 1.63 ERA in 77.1 innings pitched over 78 games. He went on to put up a 1.91 ERA the following year in roughly the same amount of work.

Last July, Watson was traded by the Pirates to the Los Angeles Dodgers, who eventually won their fifth straight NL West pennant and reached the World Series for the first time since 1988. Watson served the Dodgers well in the World Series, taking credit for two of their victories after pitching only 3.2 innings against the Houston Astros, and is one of the top free agent relievers on the market.