49ers' Alex Mack: Reconnects with Shanahan

Mack agreed Wednesday with the 49ers on a one-year, $5.5 million deal, Ian Rapoport of NFL Network reports.

Mack has familiarity with Kyle Shanahan's offensive scheme, having previously worked with the San Francisco head coach in both Cleveland and Atlanta. The six-time Pro Bowler will replace Weston Richburg as the Niners' starting center in 2021.