Heat coach Erik Spoelstra ended speculation about James' playing status approximately two hours before Monday's contest, confirming to reporters that the three-time league MVP would play against the Timberwolves.
The Miami Herald reported earlier Monday that James would have his knee examined by a team doctor once the Heat arrived in Minneapolis.
But a source told ESPN.com's Brian Windhorst that James was examined Sunday in New York by Knicks team doctors, who determined that the nine-time All-Star avoided serious damage to the knee. James' knee responded well during the flight to Minneapolis, and he did not undergo an MRI, according to the source.
James visibly attempted to loosen his knee during the third quarter Sunday but looked fine in the closing minutes, making several critical plays as Miami tied a franchise record with its 14th consecutive victory.
"His motor is limitless. I don't want to take that for granted. I don't just want to assume that he can play 40-plus minutes, but he had to do it on both ends," Spoelstra said. "Couldn't get him out in the fourth quarter and if I would have tried, he probably would have strangled me.
"He was strong and was at his strongest after 40 minutes of basketball."
James, who finished with 29 points, 11 rebounds and seven assists, ended the Knicks' final hopes when he stepped in front of a pass headed toward Carmelo Anthony and broke in alone for the slam.
"We feel like this is one of our better wins of the season, even under the circumstances that we went through tonight, a little adversity being down double digits," James said.
The last time James missed a game due to injury was Jan. 5, 2012, when he was sidelined against the Atlanta Hawks due to a turned ankle. The Heat, who also were without Dwyane Wade in that game, still managed to beat the Hawks in triple overtime, 116-109.
Information from The Associated Press was used in this report.