A year after reaching the MLS Cup final, the Red Bulls had the worst record in the league at 2-16-4 when Osorio resigned.
"It has been a difficult season for Juan Carlos and he felt that it was in the best interest of the team to step aside," said Red Bulls managing director Erik Stover in a press release. "I want to personally thank Juan Carlos for his efforts with the Red Bulls organization. It was under his leadership last season that the team won the Western Conference Championship and reached the MLS Cup Final for the first time in franchise history. We wish him well in his future endeavors."
Osorio, who came over from Chicago, led the Bulls to a 12-27-13 record.
"I want to apologize to the fans for the results this season," he said in a statement. "I want to thank the players for their hard work. I would also like to thank the club for the opportunity to coach the team for the past two seasons."
The news comes the same day Michael Lewis of bigapplesoccer.com reports that Red Bull, the Austrian company that bought the club from AEG in 2006, might sell it to FC Barcelona.
MLS has courted the Spanish club for several seasons. It has a promotional arrangement with Barcelona, which looked to move into the Miami market.
With the stadium the Red Bulls will open in Harrison, N.J., in 2010, MLS is desperate to fix what should be its flagship club. Barcelona's move into New York would give it the most prominent market into which to invest directly in MLS.
Barca star Thierry Henry has often talked of ending his career in MLS. Perhaps with NY Barca?