The 28-year-old's representatives were eager to complete a deal in August but the Bulls have elected to delay the talks until later in the season, according to CSN Chicago.
"We're not upset, Luol isn't upset. We're just looking forward to this season and next summer," claimed a source close to the player. "They were willing to wait and risk losing him next summer as an unrestricted free agent."
Due to NBA rules, Deng could opt out of the final year of his contract and speak to other franchises at the end of the season.
Deng was a first-round pick for the Bulls in the 2004 Draft.