Australian cricket team coach Tim Nielsen declined to admit that Mitchell Johnson had become a liability through the Ashes.

Commenting over the left-arm pace bowler, Nielsen said: "The last two years when we've played some pretty good Test match cricket and Mitchell has been at the forefront of that."

Nielsen said that he would neither confirm nor rule out Johnson for the Edgbaston Test, but did admit that both mental and mechanical factors were contributing to the bowler's decline.

Johnson is expected to play the third Test, after his slump in form in the opening two Tests of the Ashes series.

The coach also asserted that he could see the frustration in Johnson's face but doesn't want to let the pacer feel low.

The former wicketkeeper believes that Johnson's problems were both technical and mental. The Aussie coach also added that Clark and McDonald, who were brilliant in the tour games, were both close to Test selection.

Clark took two wickets in each innings against Northampton and McDonald came up with a second innings 75 while opening the batting, with 4-15 from his 11 overs.

Meanwhile, Australian media and cricket fans have demanded that Johnson be left out of the third Test.