Coach Jim Boylen said after the game that the decision was matchup-based, but sources told ESPN earlier Thursday that Parker won't see regular minutes going forward.
With Chandler Hutchison sidelined, Parker came off the bench Thursday and was scoreless in four minutes. He did not play in the second half.
"Well, I think it's a matchup thing," Boylen said. "It's also hard to play three 4s. It's difficult to do that. You know, this team is not about one person, one matchup. It's about the team, and you play your minutes when you're in there, and when you're not, you support the guys who are. We have a lot of games left, and we're going to need all of our people."
Boylen said he has spoken to Parker about the decision.
"Going forward, he's part of our team, and it's not about the individual, it's about the team. It's about playing your minutes the best you can," Boylen said. "We'll see what his minutes are going forward."
Parker said he doesn't expect the change in his minutes to be permanent but calls the new direction a "surprise."
"It is a surprise because I did everything I could in the time I was given," Parker said. "But it is what it is. You can't pout. You just got to keep moving."
Parker, a Chicago native who signed a two-year, $40 million deal with the Bulls over the summer, was the team's sixth man to begin the season. After the team was hit by a rash of injuries, including to starter Lauri Markkanen, Parker moved into the starting lineup last month as a power forward, his preferred position and one he played for two seasons in Milwaukee.
Markkanen returned to the starting lineup Dec. 1, and Parker took a bench role again. The Bulls also underwent a coaching change, firing Fred Hoiberg and promoting Boylen from associate head coach.
Shortly after Boylen was hired, he said he met with all Bulls players individually to discuss their role on the team. Boylen has experimented with playing Parker at small forward and power forward, and he said Parker had taken both roles in stride.
"Jabari has been great," Boylen said. "He understands. Jabari wants to make it about helping the team win. And that's what I've asked him to do."
With Parker, 23, out of the regular rotation, the Bulls and Parker's agent, Mark Bartelstein, have began discussing trading the power forward. Bartelstein and the Bulls are looking to find a "win-win" trade situation.
On Friday night, Bartelstein told ESPN that several teams have already contacted him inquiring about Parker. Financially, moving Parker may be a challenge.
Parker is averaging 15.8 points, 7.1 rebounds and 2.3 assists per game.