PHILADELPHIA (AP) In yet another setback to the Philadelphia 76ers' frontcourt, center Marc Jackson will be sidelined indefinitely with a fractured left ring finger.

Jackson broke the finger in the first two minutes of Tuesday's game against Toronto but played through the pain until the 4:14 mark of the second quarter. After an X-ray revealed the fracture, Jackson tried to convince team doctors he could still play.

``Marc was very animated and very determined,'' team president Billy King said. ``When he was informed that he would need surgery he said, 'I'll play the last 24 minutes and operate after that.'''

Jackson will undergo surgery at the Philadelphia Hand Center on Thursday. Team officials said that they would not have a timetable for Jackson's return until after the surgery.

Samuel Dalembert will likely start in place of Jackson, whose injury leaves the 76ers very thin in the frontcourt.

On Wednesday, forward Glenn Robinson saw an orthopedic surgeon at the University of Pennsylvania and learned that he will be sidelined for another one to two weeks with a high ankle sprain.

Center Derrick Coleman, who has missed nine games with a strained right knee, will be a game-time decision for Thursday's game against the Chicago Bulls.

Because of the injuries, King said that the 76ers would likely apply to the NBA for an injury exemption to open an additional spot on the active roster. If an exemption is granted, King expects to sign a free agent soon.