McManus struggled with consistency after taking over for Matt Prater, who was released at the conclusion of his four-game suspension for violating the league's substance-abuse policy. McManus missed a 33-yard attempt in Sunday's win over the Miami Dolphins and was just nine of 13 (69.2 percent) in 11 games.
Barth is a five-year veteran who spent the past four seasons with the Tampa Bay Buccaneers. He missed all of the 2013 season after suffering a torn Achilles tendon while playing in a charity basketball game. In his last active season (2012), Barth went 28 of 33 (84.8 percent), missing just one of 13 attempts between 40-and-49 yards. He also made six of nine kicks from 50 yards and beyond.
Barth doesn't have the leg of McManus, but the Broncos made the internal decision that field-goal accuracy needed to be addressed. Dumping Prater -- one of the game's best kickers a season ago -- doesn't look like the greatest move right about now.