The Lakers announced as much Wednesday, noting an MRI revealed a left knee contusion for the Michigan product.
This development comes after Mike Trudell of Spectrum SportsNet reported Wagner suffered a left knee and left ankle injury during Tuesday's contest against the New York Knicks, forcing him to miss the remainder of the game.
Wagner turned heads in his final collegiate season by helping lead the Wolverines to the Division I national championship game, where they lost to Villanova. He averaged 14.6 points and 7.1 rebounds per game while connecting on 39.4 percent of his three-point attempts.
His production was good enough to merit the Lakers selecting him with the 25th pick.
At his best, Wagner can serve as a versatile matchup problem as someone who can force opposing bigs outside of the paint with his shooting, score on the blocks and battle for boards.
He has the potential to become another talented piece in Los Angeles' young core of Lonzo Ball, Kyle Kuzma, Brandon Ingram, Josh Hart and Kentavious Caldwell-Pope, and there is no reason to rush him back for summer league action with this knee contusion.
Los Angeles will be a contender this season with the addition of LeBron James, and Wagner provides the Purple and Gold some much-needed frontcourt depth behind JaVale McGee. It is far more important he is ready to go during the regular season than in July.