Tim Tszyu wants to step up for a world title shot against American Jermell Charlo and fill the void left by an injured Brian Castano in the US in March.

Tim Tszyu could be fast-tracked into a world title fight he's owed in the United States next month.

The Sydney boxer's much-anticipated US boxing debut looked to be up in smoke this week, following a training injury to one of the card's headline acts.

Tszyu was scheduled to place his undefeated 20-0 record on the line against Terrell Gausha as the co-main event on March 19 in Los Angeles.

But a bicep injury to Argentine Brian Castano, due to fight American star Jermell Charlo in a unification bout, has thrown those plans into disarray.

As the mandatory challenger to Castano's WBO belt, Tszyu was in line to fight the winner of a unification tussle more than a year in the making that leapfrogged his own mandatory title shot.

Tszyu's camp has declared their man is ready to step up and fight Charlo on a month's notice though, frustrated that they'd otherwise have to wait until at least May to fight a fit Castano.

Charlo holds the WBC, IBF and WBA belts, with the winner of a proposed tussle with Tszyu on March 19 then able to fight Castano in a winner-takes-all clash later this year.

"I don't care who is in front of me in the ring, if Charlo is available I want it, I have been in training camp for seven weeks and I'm ready," Tszyu told News Corp.

"If Castano is injured, I can step up and fight Charlo and Castano can fight the winner."

The proactive move comes as Tszyu continues his training camp on the Gold Coast admitting he remains "in limbo" awaiting instruction on how or if the March 19 event will proceed.