The UFC dropped lightweight contender Nate Diaz from its promotional rankings on Tuesday due to his "refusal to accept bouts."

Diaz (17-9) is universally considered a highly ranked lightweight in the UFC, but he is in the midst of a contract dispute with the promotion. He hasn't fought since recording a first-round knockout over Gray Maynard in November.

"Nate Diaz has been removed due to inactivity related to his refusal to accept bouts," the UFC told ESPN.com. "There is no timetable for if and when he returns. Thus, he's been removed from the rankings."

Mike Kogan, Diaz's manager, confirmed to ESPN.com he and his client previously turned down a proposed fight between Diaz and Khabib Nurmagomedov due to financial reasons.

Diaz, 29, has publicly stated that he signed an eight-fight deal with the UFC prior to challenging Ben Henderson for the lightweight title in December 2012. He has gone 1-2 in three fights since then.

In March, Diaz went so far as to request his UFC release on Twitter. UFC president Dana White quickly stated that wasn't an option. Last month, White hinted that the dispute was over, stating during a news conference, "Nate said he's ready to fight."

Kogan declined to provide a concrete statement on Diaz's future, but made it sound as though he will continue to wait for the UFC to renegotiate his contract.

"We would like to sit down and have a conversation about our contract," Kogan said. "They said, 'No.' OK, fine. Let's wait until it's the right time to talk about it."

The UFC implemented an official rankings system in February 2013. The promotion enlists media members to vote on the rankings but maintains control of publishing results. ESPN.com currently ranks Diaz the No. 9 lightweight in the world.

Recently, UFC lightweight TJ Grant (21-5) was removed from the rankings as well due to inactivity caused by concussion. He has not fought since May 2013.

"It's whatever," Kogan said. "It's their rankings and they can do whatever they want to do. I guess they have something called 'active' and 'inactive.' It took them a year to figure out TJ Grant was seeing double, and it took them two weeks to figure out Nate Diaz wasn't fighting."