By the time he graduated in 1976, Brenly had earned All-America honors and matched Hall of Famer Mike Schmidt's school record of 10 home runs in a single college season.

[1] Brenly had his best season offensively in 1984 when, he was hitting for a .318 batting average at mid-season to earn a spot as a reserve player for the National League in the 1984 All-Star game.

[7][8] Also in 1986, Brenly broke up a perfect game attempt by pitcher Don Carman on August 20 by leading off the ninth inning with a double.

[9] Although Brenly was a good defensive catcher, he also has the dubious distinction of committing 4 errors in one inning while playing as a substitute third baseman during a game on September 14, 1986, against the Atlanta Braves.

[10][11] Brenly was playing first base during a Giants-Mets game on September 3, 1986, when Keith Hernandez hit a sharp grounder to pitcher Terry Mulholland.

When Craig was fired at the end of the season in favor of Dusty Baker, Brenly stayed on the staff for three more years.

He was then hired in November 2004 to replace Steve Stone as a color analyst for televised Chicago Cubs games.

On September 13, 2008, Brenly signed a four-year extension worth $3.5& million to continue his role as color analyst for Cubs games.

[17] Brenly again worked Division Series post-season coverage for TBS in 2009-2013 with Dick Stockton as his play-by-play partner each year.

[19] On June 3, 2021, Brenly announced in a statement that he'd be stepping away from broadcasting temporarily to reflect on comments he had made the day before on-air about New York Mets pitcher Marcus Stroman, which Aramis Ramirez said was discriminatory.

[21] 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.

[23] 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 two teams split the first four games before Arizona won on a walk-off by Tony Womack for their first postseason series win.

Paul O'Neill got on base with one out before Tino Martinez lined a home run to tie the game and send it to extras.

A 9th inning rally would end with Gonzalez lining a soft shot into the outfield to deliver a championship for Arizona.

The team had a terrible start to the 2004 season and never recovered, winning just nine games each in the first two months of the year while dealing with injuries.

He played in the Cubs and Boston Red Sox minor league systems in all or parts of eight seasons spanning 2008–2015.

[26] After retiring from the Portland Sea Dogs in May 2015, the younger Brenly took a position as the assistant bullpen catcher in the Boston organization.