The 35-year-old has played only one Test since January 2012 but now finds himself vice-captain to Michael Clarke and the preferred wicketkeeper in a team humbled by India 4-0 in March.
Selectors hope his presence will help bring some authority to a side dogged by in-fighting and poor discipline during the India tour. Haddin said he was ready to step up to the challenge.
“I was surprised when (chairman of selectors) John (Inverarity) called last night. But the bottom line is we have to find a way to bring this squad back together,” Haddin said on the Cricket Australia website.
“We are all going over there for one thing, we’ve got to get the Ashes back. Nothing else matters.
“We’ve got to come together and make sure we are successful in bringing back the urn.”
Haddin was recalled as vice-captain after Shane Watson stood down from the role over the weekend to concentrate on his batting and bowling after his controversial axing on disciplinary grounds in India.
Pundits doubted 44-Test veteran Haddin would ever reclaim his spot in the team after returning home from the tour of the West Indies in 2012 when his young daughter fell seriously ill.