Zeuge is set to make the first defence of the WBA ‘regular’ title gained with a knockout win over Giovanni De Carolis in November and Smith had been the frontrunner to nail the fight down.
With Smith unranked by any of the major organizations, WBA President Gilberto Mendoza is still considering a request from Sauerland to make a voluntary against the Briton as Ekpo is next in line.
“Sauerland Promotions sent out a special permit request to do the Paul Smith Jnr. bout but we have ordered a mandatory fight against Isaac Ekpo,” Mendoza exclusively told World Boxing News.
“The Smith fight is unlikely to be approved unless Ekpo agrees to step aside,” he added.
Number three-ranked Ekpo, 34, has worked his way to a second shot at the world title having lost to Zeuge’s compatriot Robert Stieglitz for the WBO version in 2013 and could challenge the champion ten years his junior if he decides to take the mandated shot.
German Zeuge is currently pencilled in to return to action on March 18 on home soil, with Ekpo or Smith now primed to be in the opposite corner.
Smith Jnr. had been hoping to contest a world title for the third time in his career following two defeats to Arthur Abraham in 2014 and 2015, although the 34 year-old is being forced to await a final ruling.