Brosius grew up in Milwaukie, Oregon, where he attended Rex Putnam High School before going to Linfield College.

Brosius became one of the few players to hit a home run in his first major league game, on August 7, 1991.

Brosius was the A's starting third baseman through the mid-1990s, although he played almost 300 games in his Oakland career at other positions, primarily in the outfield.

On July 18 of that year, against the Montreal Expos, Brosius caught shortstop Orlando Cabrera's foul popup for the final out of David Cone's perfect game.

In one of the most dramatic, clutch moments of his career, Brosius hit a two-out, two-run home run in the bottom of the ninth inning of Game 5 of the 2001 World Series against the Arizona Diamondbacks to tie the game and set up an extra-innings Yankees win.

The previous night, New York first baseman Tino Martinez had hit a two-out, two-run home run to tie the game in the ninth inning as well.

On December 4, 2015, the Seattle Mariners announced that Brosius would be the new hitting coach for their AAA affiliate, the Tacoma Rainiers.

[8] The team finished fourth in the tournament and failed to qualify for the 2020 Olympics in the initial rounds.