Falcons expected to add Pro Bowler Alex Mack to offensive line

— -- Center Alex Mack is expected to sign with the Atlanta Falcons, a source told ESPN's Adam Schefter, confirming multiple reports.

In Atlanta, Mack will be reuniting with Kyle Shanahan, the Falcons' offensive coordinator who held the same position with the Browns before leaving the team in 2015.

Mack will be the second major departure for the Browns in free agency as wide receiver Travis Benjamin has agreed to a contract with the San Diego Chargers.

Mack voided the final three years and $24 million remaining on his contract on March 2, becoming a free agent. The 30-year-old center had to make a decision on the opt-out by March 4.

He was a first-round pick by Cleveland in 2009, and has played every game in his six seasons with the team.

A three-team Pro Bowl selection, he is considered one of the NFL's top interior lineman.

Mack secured a five-year, $42 million contract, which included $18 million guaranteed, from the Browns in 2014 after the club used the transition tag on him. Jacksonville signed Mack to an offer sheet, which the Browns matched.

ESPN's Pat McManamon contributed to this report.