Matthew Michael Duffy (born January 15, 1991), nicknamed "Duffman", is an American professional baseball third baseman who is a free agent.

[3] At Lakewood High School, Duffy was a two-year letterwinner and led the team to a 23–12 record and a league championship in 2008.

During his 2010 season at Long Beach State, Duffy played in 30 games, starting 20 of them; averaged .244, had 86 at-bats, 8 runs, 21 hits, and 7 RBI.

In those two seasons at Long Beach State, Duffy played in 85 games, starting 74 of them; averaged .260, had 300 at-bats, 30 runs, 78 hits, and 38 RBI.

[9] He began his professional baseball career in 2012 playing for the Salem-Keizer Volcanoes of the Low–A Northwest League, hitting .247 in 182 at-bats.

[10] In his minor league career, Duffy played in 248 games, recording 942 at-bats, 149 runs, 286 hits, and 55 stolen bases.

[10] However, Duffy's MLB debut is officially recognized as May 22, 2014, as the Giants' game at the Colorado Rockies that day was suspended due to rain and resumed on September 1.

[13] In Game 2 of the 2014 National League Championship Series, Duffy scored the tying run from second base on a wild pitch in the top of the ninth inning.

[3] Duffy was invited to his first spring training in 2015, where he hit .361 and earned the Barney Nugent Award, given to the player in his first Major League camp whose performance best exemplifies the spirit of the club.

[17] On May 10, Duffy hit a walk-off, bases-loaded single in the bottom of the ninth inning to defeat the Miami Marlins 3–2.

[18] On May 12, Duffy set new career highs with 3 hits and 5 RBIs, helping the Giants to an 8–1 victory over the Houston Astros.

[25] The next night, Duffy hit a two-run, go-ahead triple in the sixth inning as the Giants came from behind to defeat the Phillies 8–5.

[30] On August 4, Duffy tied his career high with four hits, including the game-tying RBI double in the top of the eighth inning as the Giants came from behind to defeat the Atlanta Braves 8–3.

[34] Duffy was a Gold Glove Award finalist and he finished second to Kris Bryant in the NL Rookie of the Year voting.

On August 1, 2016, the Giants traded Duffy to the Tampa Bay Rays along with Lucius Fox and Michael Santos for Matt Moore.

Duffy and the Rays organization expressed their frustrations with the rehabilitation process but still remained optimistic that he would appear in the 2017 season.

At the conclusion of the 2017 season, Duffy joined the instructional and winter league Rays' affiliates with hopes to build momentum into 2018.

Following a 1-13 skid, Duffy ended his first full season since 2015 slashing .294/.361/.366 with four home runs in 132 games and was considered a front runner for the comeback player of the year award.

He did not appear in a game for the Rangers organization due to the cancellation of the minor league season because of the COVID-19 pandemic.

He did not appear in a game for the Yankees organization, also because of the cancellation of the minor league season, and became a free agent on November 2.