James, 30, underwent an MRI and a physical examination by the Cavaliers team doctor on Wednesday, which revealed the injuries. The 10-time NBA All-Star sat out the Cavaliers' last two games, both losses to the Atlanta Hawks and Milwaukee Bucks.
James will miss seven games, including a matchup with the Western Conference leading Golden State Warriors, if he is able to return as expected.
James is averaging more than 37.5 minutes, the fourth most in the NBA, while scoring the second-most points per game (25.2) this season.
The Cavaliers (18-14) travel to Charlotte to face the Hornets (10-23) on Friday.