Luka Doncic isn't your average rookie, and he knows it

LUKA DONCIC'S HELLO KITTY backpack has rarely been seen inside the American Airlines Center. Never mind the rules for Dallas Mavericks rookies.

Last season, Dennis Smith Jr. dragged a variety of his own kid-themed backpacks around to every arena, a harmless rookie rite of passage the Mavs share with many NBA teams. But why the relaxed rules for Doncic, who now carries his only on the road?

"You've got to talk to J.J. Barea," Mavs guard Devin Harris says. "J.J. gave him the pass."

Shooting guard Wesley Matthews half-kiddingly accuses Barea of being "soft" on Doncic, saying the Puerto Rican guard goes easy on the rookie who spent the previous six years in Spain because "they speak Spanish and…