James had been listed as a gametime call for Miami's home game against the New York Knicks.
He wore a mask to protect the nose, which he injured last Thursday when he was struck in the face on a drive to the basket by the Thunder's Serge Ibaka.
"My nose is still very tender, and hopefully the mask is there to protect it if an impact occurs," James said before the game. "But it is what it is, and I'm just going to wear it.
"I was targeting Thursday. I didn't want to sit out Sunday (vs. the Bulls), but obviously, it was the smartest thing to do ... just to get some more time to let the nose heal. I went through a full contact practice yesterday, and the main thing is they wanted to see how I bounced back today. I got some work in and they allowed me to go."
James is looking to finish off arguably his most productive month of the season against the Knicks. He has shot 61.3 percent and averaged 37 points, 9.5 rebounds, 5.3 assists and 3.3 steals his past four games. The Heat have won five in a row and eight of their past nine.
"I always kind of let the game come to me," he said. "It's going to be a challenge since I haven't worn one (a mask) since my second season in the league. Any little rest I can get, I can always benefit from it. I took advantage of it. My body could have used it, especially coming back from All-Star break."
Information from ESPN.com's Michael Wallace was used in this report.