49ers signing veteran center Alex Mack to a one-year, $5.5 million deal

The San Francisco 49ers have agreed to a one-year, $5.5 million deal with longtime NFL center Alex Mack, per Ian Rapoport of NFL Network. Rapoport first reported the news of Mack's impending signing earlier this morning.

The deal reunites Mack with 49ers head coach Kyle Shanahan. The two worked together in 2014, when Shanahan was the offensive coordinator for the Cleveland Browns, and in 2016, when Shanahan was the offensive coordinator with the Atlanta Falcons. Mack recently spoke with NBC Sports Bay Area about Shanahan's offense and playing within the scheme.

"What Kyle has done very well in the past has always been to link different plays and different schemes so they all look pretty much the same, but it takes advantage of the different things a defense will do," Mack said. "So, it's a very smart offense, which is fun."

Added Mack: "Kyle's an incredible coach. He's an incredible coach, great person, strong motivator, and runs an offense that is something that I'd know really well and that I'd perform very well in."

The Cleveland Browns drafted Mack with the No. 21 overall pick in 2009. He spent seven seasons there before signing with the Falcons in 2016.

Mack, 35, is a six-time Pro Bowl selection. The dependable veteran has started 16 games in all but two of his 12 NFL seasons. He missed the final two games of last season due to a concussion, which ended his streak of 90 consecutive regular-season starts.

Mack is from California and plans to spend his post-NFL days in the state. That may have influenced the center to head to the Bay Area on the tail end of his career. Mack played college football for the California Golden Bears and lives in the state during the offseason.

Mack is a member of the NFL 2010s All-Decade Team. He has 179 game appearances through his 12 NFL seasons.