The NBA champions were beaten 101-100 by the Brooklyn Nets last night, recording back-to-back losses for the first time since January.
The forward told reporters: "What you've done in the past doesn't mean you can make it happen in the present, so we've just got to have a little more sense of urgency.
"It's not doomsday right now. We're good, but we understand what we need to fix and correct."
James finished the game with 26 points, seven rebounds, six assists and two steals.