LOS ANGELES -- UFC heavyweight champion Junior dos Santos will defend his title at an unannounced card on Dec. 29 in Las Vegas. His opponent, however, is yet to be determined.

UFC co-owner Lorenzo Fertitta confirmed the promotion's plan to have dos Santos (15-1) compete on the year-end card to ESPN.com on Saturday.

"There is no contract but that's what we have penciled in my office," Fertitta told ESPN.com.

Fertitta added the reason a previously scheduled fight between dos Santos and former heavyweight champion Cain Velasquez for UFC 152 on Sept. 22 was delayed was because of a "couple nicks, nothing serious," that dos Santos suffered in training.