"He has very mild symptoms, so this test will not be categorized as a potential false positive," the university said in a statement Wednesday. "He will follow all appropriate guidelines and isolate at home."
Saban, 69, also tested positive for COVID-19 in October, but that was clarified as a false positive.
The Crimson Tide -- who rank No. 1 in the College Football Playoff rankings -- host the Tigers at 3:30 p.m. EST Saturday in Tuscaloosa, Ala.
Saban will need to isolate for at least 10 days, per Southeastern Conference protocol.
The Crimson Tide are scheduled to battle Arkansas in their season finale Dec. 4. Offensive coordinator Steve Sarkisian likely will assume head coaching duties in Saban's absence.