Superstar forward James tweaked the injury he sustained in a training camp during the Cavs' 108-94 defeat to the Chicago Bulls on Tuesday.
The 13-time NBA All-Star will consequently sit out Friday's meeting with the Orlando Magic.
"He didn't practice today. He's experienced soreness so he won't practice tomorrow, he won't play on Friday either, so [he's] pretty mad, pretty p****d off but it is what it is," head coach Tyronn Lue said.
