Bulls star Derrick Rose missed Wednesday's game against the Miami Heat because of a strained groin, leaving Chicago without its best player for a matchup between the Eastern Conference's best teams.
Coach Tom Thibodeau says he's day-to-day.
With Rose out, C.J. Watson returned from a sprained left ankle and started at point guard. Meanwhile, All-Star forward Luol Deng was back in the lineup after missing two games because of pain in his injured left wrist.
For Rose, the past few days have been difficult. He has also been limited by back and toe problems this season and missed his 11th game on Wednesday. A day earlier, he was fined $25,000 by the league for criticizing officiating and was involved in a minor car accident, although he was not injured.