But they remain optimistic it will happen sooner rather than later.
"It's still too early," Bulls executive VP John Paxson said Wednesday night, while discussing whether Mirotic may come to the NBA this summer or the next one. "We still have things we have to do. He still has a significant buyout with Real Madrid. So there's still some things we have to [get through] and we can't do it until this summer.
"But going over there earlier in December, [Bulls GM] Gar [Forman] and [Bulls international scout] Ivica Dukan were laying the groundwork to be in the game when we can be."
Paxson sounded optimistic about his discussions with the 23-year-old Mirotic, whom the Bulls made a deal for in the 2011 draft. But he isn't sure if or when Mirotic will decide to try to get out of his deal with Real Madrid.
It remains unclear how much he wants from the Bulls. But the idea of him taking the midlevel exception seems to be a thing of the past given how well he has performed in Europe.
"Our meetings with him were great," Paxson said. "Our intention, as we talked about, is to get him here sooner rather than later. But there's still a process that we have to go through. He's just coming off the Spanish championship, the Copa del Rey, where his team won and he was the MVP.
"There's a reason we went to such lengths to try and draft him a few years ago, and we're hoping to get him at some point."
Bulls coach Tom Thibodeau said he has yet to speak to Mirotic but tries to watch his games when he has the chance.
"In the offseason, I try to watch as much as I can," Thibodeau said. "I may watch some over the All-Star break. But I like what I see; he continues to get better. Hopefully he'll be here in the future."