General manager Ted Thompson says the move, which means the legendary QB no longer counts on the team's 80-player roster, was "procedural in nature" ahead of the NFL draft.
"Both [coach] Mike McCarthy and I have spoken to Brett over the past several days," Thompson said in a statement. "Brett knew this change in his roster status was coming, and he fully understood our need to make the move in advance of the NFL draft."
The 38-year-old Favre announced his retirement March 6 in an emotional news conference, although he hasn't signed his official retirement papers. Green Bay officials say they only consider that final step a formality.
"The NFL does not require a letter for a player to be placed in a reserve/retired status," Thompson was quoted as saying by The Green Bay Gazette. "Brett has announced his retirement publicly and this is simply a personnel transaction made to develop a roster opportunity for the Packers."
The team has announced it will retire the three-time MVP's No. 4 when the season starts in September.Thompson also says the team has waived three offensive linemen -- Tony Palmer, Chris Patrick and Cliff Washburn -- to reduce the active roster to 68 players.
Palmer played in a pair of games in 2007 before sustaining a season-ending neck injury. Patrick and Washburn were on the team's practice squad before signing contracts for 2008.
Information from The Associated Press was used in this report.