Australia vice captain Brad Haddin says on Tuesday that Clarke, who has been out with a lower back injury, "is pretty excited about being involved" and "is in a good spot."
Clarke has been sidelined since the 4-0 test series loss to India, forcing him to miss out on Australia's defense of its Champions Trophy title this month.
Clarke's return will boost an Australian batting lineup that has looked shaky so far on their tour of England.
The first Ashes test is at Trent Bridge, Nottingham, from July 10.
Australia fired coach Mickey Arthur on Monday and replaced him with Darren Lehmann.