Chargers coach Mike McCoy announced on Saturday that the Notre Dame product has a sprained left foot and will not play in the team's third preseason game at San Francisco next week.
Asked if Te'o would be out for a prolonged period of time, McCoy declined to specify if his inside linebacker would be out for an extended period.
"When he's ready, he'll be back out there," McCoy said.
Te'o suffered a sprained right foot during the first preseason game of his rookie season last year against Seattle. Te'o missed the rest of the exhibition season, along with the first three games of the regular season, to rehabilitate the injury.
"It's not the same injury," McCoy said. "It's something completely different."
Te'o returned against Dallas in Week 4 and immediately was placed in the starting lineup. He appeared slowed by the injury, taking poor angles to the ball carrier, missing tackles and at times reacting slowly in the run and pass game.
Te'o's overall play improved the second half of the season. He finished fifth on the team with 61 combined tackles, but he finished without a sack, interception or forced fumble in his rookie season.
Te'o had surgery this offseason to repair what turned out to be a fractured bone in his right foot. During the offseason, Te'o worked to lose weight, and said he was in the best shape of his life heading into training camp. Te'o led the Chargers with a combined six tackles in a 41-14 preseason loss to Seattle on Friday.