49ers' Austin Mack: Needs more recovery time

Mack (hamstring) will be out a few weeks, Jennifer Lee Chan of NBC Sports Bay Area reports.

Mack left the 49ers' preseason game against the Vikings on Saturday with a strained hamstring. The 24-year-old is currently competing for a spot on the 49ers' 53-man roster, and the injury will likely be a detriment to his chances.