The rehabilitation from a right-leg stress fracture that has kept Deng off the court since February is taking longer than expected.
While hopeful about returning for the Bulls' fall training camp and the preseason game against the Utah Jazz on Oct. 6 in London, Deng is not risking playing for Britain before then.
"It's a very tough decision not being able to play but it was just a tough year last year with my injury," Deng said in a conference call Monday. "The fracture of my leg was such a serious injury that I need all summer in order to go full speed and I'm not full speed yet, but I'm almost there.
"Right now it's the right decision, hopefully it will come out as a small sacrifice for my future with the Bulls and my future playing with Britain."
It is the 24-year-old Deng's first major injury.
"You learn a lot about your body, you learn a lot about work ethic and how much you have to push yourself," he said. "You want to get healthy but you also want to prove to people that you can get back to the level you were at or even better so this injury drives me to become a better player and that's really what I want to get out of this injury."
Deng, who grew up in London after his family fled conflict-torn Sudan, insists the Bulls did not influence his decision not to represent Britain in the next two months.
Britain is hosting a four-nation tournament in London featuring Israel, Poland and Turkey next month ahead of the European Championships in Poland in September.
"If I was healthy I would definitely be playing and I'm sure the Bulls wouldn't mind it," Deng said. "But because of my injury, it changed a lot of things."
"Ben is still very interested in playing for GB," Deng said. "I think Ben thought he would be staying with the Bulls so it would have been an easier summer knowing he was coming back to the same team, the same city, the same house, but now his plans have all changed around.
"He has signed for Detroit so he has to commit to them and move up there and go and work out and get to know his new teammates."
Playing in EuroBasket is a key part of the targets Britain was set by world governing body FIBA to prove the country is worthy of taking up the place for hosts at the Olympics, which start exactly three years from Monday.
"I don't usually like to get too excited too early because I think it ruins the fun, I just look forward to what's next," Deng said. "But I would be lying if I said I didn't think about 2012 a lot."
Deng is also thinking about Chicago's bid to host the 2016 Olympics ahead of the Oct. 2 vote.
"It would just be amazing, the fact that it's in London, and would then be in Chicago," he said. "I spoke to many people and I said I would love to help as much as I can because I know how much this city wants it to be here. I really believe that it would be a great place for it."