LeBron James' right foot issue has officially been classified as a "tendon injury" ... which will keep the Lakers superstar sidelined at least three weeks, the team announced Thursday.
It's unclear if James will play again this season ... as he will be reevaluated again after his time away.
The news is a big blow to the Lakers, who are trying to claw their way into playoff contention with the season winding down.
L.A. is currently 11th in the Western Conference standings with a 30-33 record ... and will need to move up at least one more spot in order to make the NBA play-in tournament.
LeBron was initially listed out of Tuesday's matchup against the Grizzlies with a sore foot ... but required more testing to figure out what exactly was wrong. He was spotted limping while wearing a big boot on his lower leg during the loss.
The Lakers have been dealing with multiple injuries recently -- Anthony Davis and D'Angelo Russell also missed Wednesday night's game against the Thunder ... but despite being short-handed, the Purple and Gold were able to pull out a win.
LeBron was clearly thrilled with his teammates ... saying, "Great Win Fellas!! #LakeShow"