In his career, he played in Major League Baseball (MLB) as a first baseman for the Milwaukee Brewers, San Diego Padres, Toronto Blue Jays, and Cincinnati Reds.

He began co-hosting Blair and Barker after Sportsnet parted ways with Gregg Zaun.

After spending the 2001 season in the minors, the Brewers traded him to the San Diego Padres on March 24, 2002, in exchange for Dusty Wathan.

[5] He received a September call-up with the Blue Jays and on September 3, 2006, Barker recorded his first hit as a Blue Jay, a home run off Boston Red Sox starting pitcher Josh Beckett.

After the 2007 season, Barker signed a minor league contract with the Cincinnati Reds and played for the Triple-A Louisville Bats the entire year.