Tim Tszyu's WBA super-welterweight interim world title fight against unbeaten American Virgil Ortiz was called off Friday on doctor's orders with the Australian still struggling from a nasty head injury.

Tszyu lost for the first time in his career on a split-decision to American southpaw Sebastian Fundora when he put his WBO super-welterweight belt on the line in Las Vegas in March.

During the bout he struck his head on the left elbow of his towering challenger in the second round, with a deep gash opening up and blood blinding him for much of the fight.

He was due to meet Ortiz in Los Angeles in August on a blockbuster card headlined by the unbeaten Terence Crawford facing Uzbekistan's light-middleweight world champion Israil Madrimov.

But medical advice has put paid to Tszyu's plans.

"The highly anticipated WBA super-welterweight interim world title showdown between former WBO champion Tim Tszyu and Virgil Ortiz has been cancelled," his promotor No Limit Boxing said on social media.

"Medical advice provided to Tszyu requires him to take additional time for his head wound to heal."

A win against Ortiz would have seen Tszyu well positioned to challenge either Madrimov or Crawford, or the winner of Fundora's next bout, against Errol Spence.