England captain Joe Root says he will not be losing any sleep over "world-class" Alastair Cook's poor start to the Ashes.Cook failed to reach double figures in both innings of Australia's 10-wicket victory at the Gabba.

Root expects his prolific predecessor to put that Brisbane failure behind him and show what he is capable of in the remainder of the series. "Cookie is a world-class act, he has scored over 11,000 Test rounds. He has been one of our most consistent performers for over 10 years." Root said on the eve of the second Test at the Adelaide Oval.

"His experience, his success, of course, it isn't the ideal start to a series but when you have all of that behind you and the ability he has, it's not something I'm going to lose sleep over. I'm sure over the series he is going to make massive contributions and perform really well for us."

England has a doubt over Moeen Ali (finger) for the second Test, but Root said the all-rounder may play without bowling.