Coach Nick Saban said Monday that Pierschbacher would miss the next game, against Mercer this Saturday, "and then probably a medical decision for [Auburn]."
Pierschbacher suffered the injury during the first quarter of Saturday's 31-24 win over Mississippi State and was unable to return to the field.
Many offensive linemen have been able to return from a high-ankle sprain quickly, giving hope that Pierschbacher could possibly return to play in the season finale against No. 10 Auburn in two weeks.
Pierschbacher, a fourth-year junior, has been a starter for much of the last three seasons.
J.C. Hassenauer replaced him during the game against Mississippi State.
Saban also said that defensive back Minkah Fitzpatrick, who injured his hamstring against LSU on Nov. 4, is day-to-day.