Stingley, a junior, originally injured the foot in the summer but was able to return and play in the Tigers' first three games this season.
He reinjured his foot last month and has missed the past two games.
Tigers coach Ed Orgeron said there is no timetable for Stingley's return.
"You just have to look at it and play it by ear," Orgeron said on the SEC teleconference Wednesday. "It's one of these injuries that was nagging. He went to the doctor to have it taken care of.
"We don't know when or if he will be back. If not, we have to carry on."
"I appreciate all of the support from LSU and the fans," Stingley said in a statement. "I'm doing all that I can to return to the field as soon as possible. I want to finish out the season with my teammates and I will do everything I can to get healthy so that I will be able to play again this year."
Stingley has been one of the best defensive backs in the SEC since he arrived on campus.
In 2019, he ranked second in the country in passes defended and was named to the SEC All-Freshman Team and was selected as SEC Newcomer of the Year by The Associated Press.
In 2020, he recorded 27 tackles, had 2.5 tackles for loss and broke up five passes, and he was named first team All-America by the American Football Coaches Association for the second straight year.
ESPN's Mel Kiper Jr. lists Stingley as his third-best player eligible for the 2022 NFL draft.
LSU, which lost to Auburn last weekend and fell to 3-2, goes on the road to play undefeated Kentucky on Saturday.