Jones initially declined to meet Sonnen on eight days' notice after Dan Henderson was forced off a Sept. 1 card with a knee injury.

Following Jones' refusal, Zuffa, the Las Vegas-based promotional company that owns and operates UFC, opted to cancel UFC 151, a first during almost 12 years of business.

Jones (17-1) instead agreed to fight Vitor Belfort on Sept. 22 in Toronto, where he retained the title via fourth-round submission. Early in the fight, however, Belfort secured an armbar that hyperextended the champion's right arm before the submission was denied. As of two weeks ago, Jones' elbow had not fully recovered, necessitating the April date, White told the Los Angeles Times.

Sonnen (27-12-1) is best known for two contests against UFC middleweight champion Anderson Silva. The Oregonian fell short of defeating Silva in July, suffering a second-round technical knockout.

Two years earlier, the strong wrestler pushed Silva into the fifth round before succumbing to a triangle choke.

Sonnen was assigned to face Forrest Griffin at UFC 155, Dec. 29 in Las Vegas, before being moved to face Jones. The contest with Griffin would have been Sonnen's first at light heavyweight since he debuted in the UFC in 2005.

Griffin is healthy, a representative for the former light heavyweight champion told ESPN.com. He expects to participate on the main card of UFC's year-end event in Las Vegas, which is headlined by a heavyweight title showdown between Junior dos Santos and Cain Velasquez at the MGM Grand Garden Arena. No opponent has been named.