Diggs, who is the brother of Minnesota Vikings wide receiver Stefon Diggs, sustained the injury during Saturday’s 65-31 win at Arkansas.
The junior had a season-high seven tackles and a pass defensed in that contest, with his tackle total just three shy of Dylan Moses’ performance for top honors on the team.
Freshman Patrick Surtain II is expected to replace the 6-foot-2, 199-pound Diggs for No. 1 Alabama (6-0), which hosts Missouri on Saturday before traveling to Tennessee on Oct. 20.
“We’re obviously very thin and need some guys to step up and develop,” Saban said. “But Patrick has played quite a bit at his position. We do have two guys that have some experience, but we don’t have a lot of depth right now.
Diggs has recorded 20 tackles and an interception in six games this season. His pick came off a Hail Mary in the Crimson Tide’s 56-14 victory over Louisiana on Sept. 29.
Surtain, who is 6-2 and 202 pounds, has 12 tackles and a forced fumble this season. He had three tackles — including one for a loss — versus the Razorbacks.