Although pre-season friendlies are notoriously tame affairs, De Jong was his usually tough-tackling self when, 10 minutes in, he clattered into the 20-year-old German midfielder.
Guardiola was forced to withdraw Kimmich midway through the first half due to the knock he picked up from the Dutchman's tackle and the coach was still furious when the half-time whistle was blown in Munich.
The former Barcelona boss began ranting at De Jong inside the tunnel, gesturing wildly towards the defensive midfielder, who had to be refrained from charging towards Guardiola by his Rossoneri team-mates.
Guardiola refused to discuss the incident at length after the Bavarians finished 3-0 winners in the Audi Cup semi-final, but he did stress the dejection he felt on behalf of Kimmich, whom he lauded as one of the Bundesliga's top talents.
"I told De Jong that I was sad for Joshua," he told reporters. "He won't be able to play in the final [against Real Madrid] and perhaps he'll be out even longer than that. He certainly will become one of the best German players in the next 10 years."
Milan boss Sinisa Mihajlovic slammed his counterpart's reaction by highlighting the physical nature of the sport Bayern take part in, which he claims is nothing like the solitary and safe nature of ballet.
"We play football, this is no ballet and fouls are part of the game," the San Siro trainer added. "This is no friendly, this is a tournament to prepare for the season."
De Jong has a reputation of afflicting pain on his opponents, having infamously kung-fu kicked Xabi Alonso in the chest in the 2010 World Cup final between Netherlands and Spain.
