Velasquez was been left off the list of 16 fan vote fighters vying to join light-heavyweight title-holder Jon (Bones) Jones on the cover of "EA Sports UFC" after failing to come to terms with video game developer Electronic Arts.
"I just think that Cain felt he's the heavyweight champion and he doesn't want to be in a vote to see if he should be on the cover," White told a conference call Tuesday.
"I can't blame him for that," he added.
The UFC's eight other champions did sign the dotted line: Jones, Demetrious Johnson (flyweight), Dominick Cruz (bantamweight), Jose Aldo (featherweight), Anthony Pettis (lightweight), Montreal's Georges St-Pierre (welterweight), Chris Weidman (middleweight) and Ronda Rousey (women's bantamweight).
The other candidates are Michael Bisping, Daniel Cormier, Ben Henderson, Johny Hendricks, Urijah Faber, Alex Gustafsson, Junior Dos Santos, Chael Sonnen and Miesha Tate.
The cover vote will run through Dec. 1, via a weekly head-to-head elimination tournament. Fans can make their picks at www.UFC.com/covervote.
Previous versions of the UFC video game were made by THQ, which featured Forrest Griffin, heavyweight champ Brock Lesnar, Anderson Silva and St-Pierre on its game covers.
The video game, currently under development at EA Canada in Vancouver, is slated for release in the spring for the Xbox One and PlayStation 4.