Baker, Brenly stayed on the staff for three more years. In 1998, Brenly was hired as a broadcaster for the new expansion team in the Arizona Diamondbacks for Fox Sports Net Arizona. He was at the position for three years, which included broadcasts across national Fox platforms. The firing of Diamondbacks manager Buck Showalter a day after the 2000 season lent an opportunity for Brenly, who was one of the seven candidates interviewed by Arizona alongside Chris Chambliss, Carlos Tosca, Clint Hurdle, Tom Spencer, Ron Hassey, and Terry Francona; Brenly and Francona were the final two considered. On October 30, he was signed to a three-year, $2 million contract. He was cited by general manager Joe Garagiola Jr and managing partner Jerry Colangelo for his "baseball knowledge, work ethic and attitude", which contrasted with the "micromanaging" Showalter, who had won 250 of 486 games but had failed to reach past the National League Division Series. With veteran stars such as Luis Gonzalez, Randy Johnson, and Curt Schilling, expectations were good for the team to win when they still had a chance to do so. The Diamondbacks won 92 games in his rookie season, finishing two games ahead of the San Francisco Giants, the defending NL West champion. In the 2001 National League Division Series, they played against the St. Louis Cardinals. The two teams split the first four games before Arizona won on a walk-off by Tony Womack for their first postseason series win. In the 2001 National League Championship Series against the Atlanta Braves, they split the first two games against each other before they rolled the next three games over Atlanta (with Schilling and Johnson winning three of the four games) to clinch the National League pennant. In the 2001 World Series, they were matched against the New York Yankees, who had won the last three World Series matchups and were looking for a four-peat with heavy odds in their favor. As per the tradition of the time for home-field advantage in the World Series having the National League host in odd-number years, Arizona hosted the first two games. They outscored the Yankees 13-1 in those games with Johnson and Schilling coming through with decisive victories. When the Series shifted to New York, Brenly's team dealt with adversity. Game 3 saw them held to three hits and one run while New York narrowly won. Schilling was sent out