McGruder, in his second NBA season, will likely undergo surgery, league sources said.
McGruder has been a success story for the Heat out of their development program and was slated to start for the second consecutive season. McGruder, a 6-foot-5 guard able to defend multiple positions, averaged 6.4 points and 3.3 rebounds in 78 games (65 starts) for the Heat last season.
The Heat will now likely start Josh Richardson in place of McGruder. Richardson, who signed a four-year, $42 million extension before the season, has had a strong preseason, averaging 13.6 points per game.
McGruder, 26, went undrafted out of Kansas State in 2013.
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