England's Ben Stokes said the knee issue that hampered him in the Ashes opener was a flare-up of an older injury and the all-rounder is confident he can manage it going into the second match in Adelaide this week.

Stokes scored five and 14 in the nine-wicket defeat by Australia in Brisbane and bowled only 12 wicketless overs after jarring his knee.

It was his first competitive match since July after a mental health break and rehabilitation following surgery on a broken finger.

"Having a long break is going to show itself, but there are no excuses," Stokes wrote in his column for The Mirror.

"I didn't do anything whatsoever except take a catch and bowl a few no balls so the one positive is I probably can't get much worse.

"People will have seen me rubbing my knee from time to time when I was in the field, but rest assured I'm fine. It's an old injury that flares up every now and again, but I know how to manage it.

"It just gets a little bit uncomfortable in and around my cartilage, but it just looks worse than it is by the way I try and get off it as soon as I can."

England skipper Joe Root has backed Stokes to contribute more in the remainder of the series and was hopeful the issue would not restrict him.

"Obviously, he had a bit of a jarring of his knee so hopefully it's just something he's shaken off now and you can see him back at full intensity and it gives us all options on the table," Root said.

The second test in the five-match series begins on Thursday.