The 49ers signed Mack to the active roster from their practice squad Tuesday, Adam Schefter of ESPN reports.
Mack will get the promotion after news broke that rookie third-round pick Tyrion Davis-Price (ankle) will be sidelined for a few weeks. The team already lost Elijah Mitchell (knee) to injured reserve, so Mack will compete with undrafted rookie Jordan Mason for backup snaps behind Jeff Wilson. The former Colt has amassed at least 1,000 yards from scrimmage twice in his career, but he's struggled to stick in the NFL since he suffered a torn Achilles tendon in September 2020.