Berthiaume's first-ever television play-by-play experience came on the final day of the regular season in 2011 when he called the Yankees-Rays game that featured an amazing comeback by the Rays and a walk-off home run by Evan Longoria to clinch a playoff berth for Tampa Bay.
The veteran Baseball Tonight co-host followed that up by broadcasting the epic NCAA Tournament game between Stony Brook and Louisiana State University this past June. The game featured game-tying homers by LSU in the ninth, 10th and 11th innings and was eventually suspended due to rain.
Berthiaume was formally introduced along with analyst Bob Brenly in a news conference at Chase Field on Monday. They replace play-by-play man Daron Sutton and analyst Mark Grace.
The pair are very different when it comes to experience, with Berthiaume a relative newcomer to the play-by-play world, while Brenly has long been recognized as one of the best analysts in the business.
Berthiaume acknowledged his lack of experience when he visited with team president/CEO Derrick Hall during the interview process.
As the two strolled around an empty Chase Field that day, Berthiaume said to Hall, "It takes a lot of guts to consider me for this position because I haven't done a lot of games."
Hall replied, "I wouldn't have you here if I didn't believe in you and if I didn't like the work I've already seen."
The D-backs' brass watched both the Yankees-Rays game and the Stony Brook-LSU contests in their entirety.
"He was tremendous," Hall said. "I really like his calls in the game. His home run calls, close plays at the plate, you can tell he's got the talent and ability to do it. I think one day we're going to look back and be very proud of the fact that he started here for what I believe is going to be a very long and successful career."
Berthiaume was told less than 24 hours before the Yankees-Rays game that he would be broadcasting it, but he jumped at the chance and after the game told his bosses at ESPN that he had a new career plan.
"I'm a baseball junkie, that's my passion," Berthiaume said. "I don't really have interest in anything else sports-wise. It's all baseball all the time for me, and so the more I got involved in that, the more I wanted to be at the ballpark every day."
While Berthiaume is charting a new career course, Brenly is returning to a place where he had tremendous success.
The former big league catcher teamed with Thom Brennaman to form the organization's first broadcast team in 1998, and after three years in the booth, he became the team's manager, replacing Buck Showalter.
In his first year as manager, Brenly led the D-backs to the 2001 World Series title, and he remained in that position until being dismissed during the 2004 season.
After leaving Arizona, Brenly broadcast games for the Cubs before the D-backs were able to hire him following the 2012 season.
Brenly and his wife, Joan, have lived in the Phoenix area since 1997 and decided it was time to return home.
"I've dragged her around in and out of cities in the Minor Leagues and in the big leagues with very little concern as to what she wanted to do," Brenly said. "And at this stage of our lives, I think we're in union that this is where we want to be. It's going to be a great opportunity for me with the organization and working with Steve and the Diamondbacks, and it's a great opportunity for her to get back home with her friends. Everything said this was the place to be."
"It's nice to have Bob back again with his familiarity here," Hall said. "And I believe he's the best color analyst in the game."
Steve Gilbert is a reporter for MLB.com. Read his blog, Inside the D-backs, and follow him on Twitter @SteveGilbertMLB. This story was not subject to the approval of Major League Baseball or its clubs.