President Obama Sits Courtside at Chicago Bulls Game

The president's Bulls faced off against LeBron James & the Cleveland Cavaliers

— -- When in Chicago, you cheer for the Bulls, and President Obama did just that Tuesday night when he attended the Chicago Bulls season opener against the Cleveland Cavaliers.

During an overnight trip to Chicago, Obama mingled with fans and sat courtside at the United Center as he watched his hometown team take on LeBron James and the Cavaliers. It was a surprise appearance by the president, who has been dubbed the basketballer-in-chief, given his love of the game.

The president was seen cheering for his team when they scored and throwing his hands in the air when the Bulls missed shots.

While his loyalty lies with the Bulls, the president has shared kind words about James, calling him the "heart of the Cavs." In 2013, Obama famously told James, widely considered to be the best player in the game, "It's your world, man."

Earlier in the day, James said it would be an "honor" to play in front of the president.

"He loves the game of basketball," James said Tuesday morning. "We all know that. It's an honor for me to be a part of a venue and a spectacle that the president would like to come and watch. It's an honor for sure."