Team officials made the announcement Wednesday before a 134-118 loss at Indiana.
Kessler, a first-team all-rookie selection last season, was injured during a season-opening loss to the Sacramento Kings on Oct. 25. After initially trying to play through the pain, doctors determined he injured the ulnar collateral ligament and that the best remedy would be avoiding contact for two more weeks. Then he will be re-evaluated.
He's averaging 8.3 points and 7.9 rebounds.
"We check in our players every day on how they're feeling and it reached a level in the last day or so, it garnered a lot more attention," coach Will Hardy said. "Walker is not somebody who's going to make excuses for his play. So I'm not going to do that, either.
"You're going to see some lineups that we haven't seen yet. Obviously, starting a couple of guys who are going to be making their first starts of the year."