The trade deadline could spell the end of the Baltimore Orioles' current bullpen.

Sources tell Fox Sports' Ken Rosenthal that owner Peter Angelos gave approval to GM Dan Duquette to trade the team's top relievers and outfielder Seth Smith.

Closer Zach Britton has already been tied to the Los Angeles Dodgers and on Tuesday, an industry source told MLB.com's Mark Feisand that the Chicago Cubs could be the favorites to land the talented lefty. Rosenthal mentions the Houston Astros as another possible fit.

Now that Duquette has approval to trade his best relievers, righties Brad Brach and Darren O'Day could draw more interest. Britton, O'Day and Brach are all under club control beyond the 2017 season.

Smith, meanwhile, is slashing .268/.328/.448 with 10 homers and 21 RBIs in 67 games this year, his first with the Orioles. The 34-year-old is set to be a free agent at the end of the season.

Catcher Welington Castillo could also generate some interest, Rosenthal notes. Castillo signed a one-year, $6 million deal with the O's this past offseason, which includes a $7 million team option for 2018.

Per Rosenthal, the Orioles aren't willing to listen to offers for outfielder Adam Jones, third baseman Manny Machado and reliever Mychal Givens, who's under team control until 2021 and is currently drawing trade interest.

Baltimore entered Tuesday at 43-49, eight games back of the Boston Red Sox and tied with the Toronto Blue Jays for last place in the American League East.

-- Alex Tekip