With Toomua unavailable and Christian Lealiifano missing most of the pre-series training camp because of the birth of his first son, coach Michael Cheika fielded an untried centre partnership in the first test defeat in Brisbane last Saturday.
While Samu Kerevi and Tevita Kuridrani provided plenty of tackle busting runs, their combination was a major departure for Australia, who have used a second playmaker at inside centre for several years.
Faced with a game they must win to keep the series alive in Melbourne on Saturday, Toomua and Lealiifano, who played the best part of an hour off the bench at Lang Park, offer Cheika the option of returning to that model.
News that makes sense
Your trusted source for staying up-to-date with the world around you. Get free daily news updates and analysis, straight to your inbox.
Cheika was quite pleased with how the Kerevi-Kuridrani partnership performed and Lealiifano also thought they went well until a head knock to winger Rob Horne forced a rejig of the backline.
"It was difficult with the limited ball they had, but I thought Samu and Tevita were very dangerous when they had the ball and the opportunity to run," Lealiifano told reporters in Melbourne.
"We know the quality of player they are. With a bit more ball hopefully they can do a bit more damage."
Lineout caller Rob Simmons, who came off the pitch with a back injury in Brisbane, is still a doubt for the second row on Saturday.
Although England stole a couple of lineouts during their 39-28 first test victory, reserve hooker Tatafu Polota-Nau was not concerned that it was a weakness the tourists could exploit.
"We were just inaccurate at times and they capitalised on it," he said. "In any test match, any mistake you make will definitely get pounced upon.
"It's more so for us to try and make sure we stick to our policies and also believe in them."
(Reporting by Nick Mulvenney; Editing by Ken Ferris)
