CHICAGO -- After another setback while ramping up the rehab of his left knee, there is increasing pessimism that Chicago Bulls point guard Lonzo Ball will return to the lineup this season, sources told ESPN's Adrian Wojnarowski.

No final decision has been made, but a meeting in the coming days that is expected to include Bulls officials and Ball's representatives at Klutch Sports is more and more likely to culminate with shutting down Ball for the rest of the season, sources said.

"I would imagine in the next day or two we'll probably have a little bit more once everybody sits down and talks," Bulls coach Billy Donovan said before Tuesday night's 127-106 home loss to the Milwaukee Bucks. "It's disappointing from the standpoint you were hoping that the time he had off would help maybe propel him going forward to do a little bit more. But that certainly hasn't been the case."

After Tuesday, the Bulls have three games left in the regular season.

Ball, who has not played since Jan. 14, had surgery on his knee in January to repair a slight meniscus tear.

He has remained sidelined longer than the team's initial timeline for his return when his knee did not respond to the rehab process. Chicago pulled back the ramp-up process for 10 days at the end of March with "hope" the extra rest would allow him to recover, but Ball experienced a setback.

Donovan declined to speculate whether the team would be comfortable having Ball play in the postseason if he didn't return during the regular season. He said the team was focused on getting Ball to stop experiencing pain in the knee.

Despite Tuesday's loss, the Bulls clinched their first playoff berth since 2017 after the Cleveland Cavaliers lost to the Orlando Magic. They are in sixth place in the East, one game behind the Toronto Raptors.

"I think the biggest thing they're trying to figure out before we can do anything is try to eliminate his discomfort and any pain that he's feeling," Donovan said. "This period of taking some time off, letting it calm down and trying to get him back started again, there was a hope that maybe it would help, and it probably hasn't helped as much as we would've liked to."

In his first season in Chicago, Ball was averaging 13.0 points, 5.4 rebounds and 5.1 assists. He has played in just 35 games, which would be the fewest of any season in his five-year career.

"All these guys love to play, and he wants to play," Donovan said. "He is, like any player, disappointed that he can't be out there and it's not progressing, but he's dealt with it and taken it in stride. And to his credit, he's tried to do everything that he can do to get himself back feeling good."

Chicago also was without guard Zach LaVine for Tuesday's game because of left knee soreness. The team has been managing LaVine's knee injury for the past few weeks, especially on back-to-backs.

The Bulls will host the Boston Celtics on Wednesday in Chicago.