The 23-year-old was convicted of aggravated arson in July 2012 and sentenced to 45 months behind bars after he set fire to his rented Munich home in September 2011.
However, he will now be allowed to work with Bayern's reserve team as part of his rehabilitation programme.
"With this step, Breno has the chance to reintegrate himself back into society as soon as possible," a spokesman for Munich's Stadelheim prison told German magazine Focus.
"Breno is as fit as a prison inmate can be."
Breno's day release is subject to a curfew and he will be required to return to prison by a set time each evening.