Deng was traded to the Cavs in a deal that sent Andrew Bynum, who was subsequently released, and three future draft picks to Chicago.
"It will probably be weird. I love Luol, he's my brother. But when that ball goes up, he's not going to be my brother when the ball goes up," Noah said, ESPN reports.
The Bulls have used the Deng trade as a rallying point, as they have now won eight of their last ten games.