The news comes a few weeks after rumors emerged that the Broncos were not happy with their kickers. Barth has been good on field goals for Denver (15-of-16 last season plus all 15 PATs), but the team wants a kicker who also kicks off well.
Brandon McManus, who was excellent on kickoffs last season, has seemingly won the kicker job. The team must feel that McManus has improved as a kicker, because he was inconsistent last year, going 9-of-13 on field goal attempts.
The Broncos may also bring in another kicker once teams start making cuts, but there's been speculation that McManus is the guy going forward.
Barth, 29, signed with Denver last season when McManus was struggling on field goals.
McManus, 24, had started the 2014 season as the team's kicker. Both Barth and McManus had finished the season with Denver and competed in training camp this summer.
Denver's specialist competitions are probably wrapping up now, as Britton Colquitt, who took a pay cut earlier this month, is likely to beat out Spencer Lanning at punter.
Neither the Broncos nor Barth have yet commented on the release.