Thibodeau and Bulls management have reportedly had a contentious relationship.
Stein reports the Bulls are increasingly likely to fire Thibodeau, even though the coach has around $9 million remaining on his contract over the next two years.
On Wednesday, Sporting News reported that Bulls players were told that Thibodeau wouldn't return to the team.
In five seasons as Bulls coach, Thibodeau has led the team to the playoffs every year, but Chicago advanced past the second round just once, in 2010-11.
- Stanley Kay