The team says Noah will likely miss five days after being poked in the left eye during practice on Wednesday.
The team said on Friday that the injury left Noah with blood in the front chamber of his eye. He'll be monitored daily by the Bulls' medical staff.
Noah averaged 6.6 points and 5.6 rebounds in 74 games as a rookie last season.
The Bulls take on Dallas at the United Center on Thursday in their preseason opener.