James, who re-signed with the Cavaliers after four trips to the Finals with the Miami Heat, said his new team will need to go through adversity before it can reach its potential.
"[The Bulls] are a team that's much better than us right now just off chemistry," James said. "They've been together for awhile, we've got a long way to go."
"You've got to go through something to create a bond; that means for the worse," James said. "We've got to lose ballgames that we think we should've won, we've got to get into an argument every now and then just to test each other out."
The Cavaliers also traded No. 1 picks Andrew Wiggins and Anthony Bennett for three-time All-Star Kevin Love. During the offseason, Cleveland also signed several veteran players, including Shawn Marion, James Jones and Mike Miller. Jones and Miller each won championships with James in Miami.
The Cavaliers and Bulls play a preseason game Monday night in Columbus, Ohio, and it will be the first time James, Love and point guard Kyrie Irving appear in a game together.
First-year head coach David Blatt, who has no prior coaching experience in the NBA, replaces Mike Brown. He said he has a good idea of what to expect when the trio makes its debut Monday.
"We haven't had the opportunity to see them all together as yet," Cavs coach David Blatt said.
"I have an idea in my mind, I have a feeling about it. Is that tried and true? Up to this point, honestly it's not. ... But I see them at practice and I obviously know the players, their skill-set and their basketball IQ and their willingness to play together, so I'm pretty optimistic about it."
The first regular-season game between the Cavaliers and Bulls will be on Halloween in Chicago.
- Paul Palladino