Gibson, 29, has not played since spraining his ankle on Feb. 27 against the Minnesota Timberwolves. Bulls coach Tom Thibodeau said Gibson will test his ankle in pregame warmups.
Chicago has gone 3-6 without Gibson. In 49 games this season, Gibson has averaged 10.6 points and 6.6 rebounds.
Gibson is only one of several key Chicago players dealing with injuries. Shooting guard Jimmy Butler is still out of the lineup as he recovers from a shoulder injury. Thibodeau said he is "real close" to returning to the lineup, according to Greenstein.
Point guard Derrick Rose had knee surgery last month, but the team is optimistic that he will be able to return before the playoffs.
Center Joakim Noah is not injured, but has been given a 32-minute limit on his playing time.
The Bulls are 41-28 and the No. 4 seed in the Eastern Conference. They are a half-game behind the Raptors and a half-game ahead of the Washington Wizards.
- Paul Palladino