Braun said in an interview last week that he's not worried about his swing getting messed up from the HR derby contest.
"WE all play HR derby every day before the games," he said. "You can't be worried about your swing, at least I'm not."
Something about this dude tells me he might be relaxed enough to just go out there and pound it! He also has the highest HR/at bat ratio (1:16.2) over a career. He also had his highest HR total in June.