David Ortiz retiring after 2016 season

Boston Red Sox slugger David Ortiz will retire at the end of the 2016 season, ending a 19-year career in which he became a New England legend for his postseason heroics.

Ortiz will announce his retirement on Wednesday, his 40th birthday, according to a person with direct knowledge of Ortiz's plans. The person spoke to USA TODAY Sports on condition of anonymity because Ortiz's plans have not been made public.

Fox Sports first reported Ortiz will retire after next season.

Watch: David Ortiz's 13 most memorable moments

Ortiz finished 2015 with 503 career home runs, cementing his status as one of the game's greatest designated hitters. But he'll likely be better remembered for his heroics in the 2004 postseason - when his walkoff home run helped spur a comeback from a 3-0 deficit against the New York Yankees in the American League Championship Series - and in 2013, when he earned World Series MVP honors.

That six-game conquest of the St. Louis Cardinals concluded a third World Series title for the Red Sox and a decade-long run of dominance that included seven playoff appearances. The run began in 2003, when the Red Sox signed Ortiz as a free agent after the MInnesota Twins opted to release him.

The Red Sox fell one game shy of the World Series that year, losing in seven games to the Yankees. They reversed that result, however, along with an 86-year championship drought in 2004 with their historic comeback from a 3-0 hole. That run began with Ortiz's 11th-inning Game 4 home run off Yankees reliever Paul Quantrill.

In 2013, Ortiz dominated the Cardinals in the Fall Classic, batting .688 (11 for 16) with two homers, six RBI and a sublime 1.948 on base plus slugging (OPS). That culminated a season in which he further cemented his status as a New England folk hero. Five days after the Boston Marathon bombing, Ortiz took the microphone during a pregame ceremony at Fenway Park and told the crowd: "This is our (bleeping) city. Nobody is going to dictate our freedom. Stay strong."

Ortiz hit 447 of his 503 home runs as a designated hitter, a statistic that opens up his Hall of Fame candidacy to significant debate. Also significant: A failed drug test in 2003, a season in which major leaguers submitted to confidential testing. However, the New York Times reported that Ortiz - along with Manny Ramirez - failed tests that season. Ortiz did not test positive in the 12 seasons since Major League Baseball enacted penalties for testing positive for perfomance-enhancing drugs.

Nightengale: Without a doubt, David Ortiz is a Hall of Famer

He addressed his positive test in an April essay for The Players' Tribune, blaming tainted supplements for the reported result: “I never knowingly took any steroids. If I tested positive for anything, it was for something in pills I bought at the damn mall. If you think that ruins everything I have done in this game, there is nothing I can say to convince you different."

Contributing: Bob Nightengale

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