Braun will attend as a fan of two Brewers teammates. First baseman Prince Fielder and second baseman Rickie Weeks are in the State Farm Home Run Derby on Monday night and the NL's starting lineup on Tuesday.
Braun joins a list of stars who have had to pull out because of various injuries. Phillies outfielder Shane Victorino and Yankees infielders Derek Jeter and Alex Rodriguez have also been replaced on the rosters.
"It's unfortunate for baseball," Braun said. "Obviously, you want all of those guys to be there and be part of it, but injuries are also part of the game and unavoidable.
"I'll be there for sure. The fans voted me in, and the least I can do is be there."
Braun's decision to withdraw was made official during Saturday's Brewers-Reds game after he conferred with Milwaukee general manager Doug Melvin, manager Ron Roenicke and head athletic trainer Roger Caplinger. Braun has not played since July 2, when he was hurt breaking out of the batter's box in Minnesota.
An MRI scan Wednesday showed inflammation of a tendon behind Braun's left knee and explained why he was feeling discomfort in both his hamstring and calf.
"While he's making progress, it didn't feel comfortable to the point of being able to go out there and give 100 percent," Melvin said. "It's a little bit risky."
That risk is magnified, Melvin said, because All-Star starters are required to play at least three innings.
"The concern was not so much going out there and swinging the bat as being in the field," Melvin said. "We all just felt that the best thing is to make sure he doesn't aggravate it and he's ready for the second half."
Braun is not expected to start Sunday's first-half finale against the Reds, and he will confer again with club officials before the Brewers resume play Thursday in Colorado to decide whether he needs to go to the 15-day disabled list. Brewers assistant athletic trainer Dan Wright is part of the NL's medical staff and will oversee Braun's treatment during the break.
By holding him out of the All-Star Game, the Brewers reserve the right to backdate a DL stint to July 3, meaning Braun would be eligible to return July 18.
The Brewers had been saying all along that Braun was day to day, but it turns out that was a stretch. He said Saturday that he "knew I wasn't going to play today a week ago."
"We've kind of had a timeline, a progression," Braun said. "Once you're out for a little while, it's a progression you have to go through. I hadn't swung or done anything for a while, so I had to hit off the tee, then soft toss, then play catch.
"Now, today is the first day I'm going to be allowed to take batting practice, take some fly balls and attempt to jog for the first time in five days. I've kind of known all along that it was going to be a process."
Braun said he didn't want to give the Brewers' opponents -- the D-backs and Reds -- a competitive advantage by coming clean about his unavailability.