The admission is included in a new book, Coach, released by the Australian head coach on the eve of the home Test series against South Africa.

All-rounder Watson was dropped after the first Test in Cardiff last year, signalling the end of his Test career, while the same match was Haddin's last as well after selectors stuck with Peter Nevill following the veteran's withdrawal from the second Test at Lord's so he could be with his seriously ill daughter.

Australia lost by 169 runs at Sophia Gardens and conceded the Ashes after being blown away in the third and fourth Tests at Edgbaston and Trent Bridge, after which there was an exodus of retiring players, including Watson, Haddin, captain Michael Clarke and Chris Rogers.

Lehmann admits now he had put his affection for Watson and Haddin as team men ahead of their declining performances and that had clouded his judgment.

"I love 'em. I still love 'em," Lehmann told Fairfax Media on Friday. "But if you were looking on raw, hard performances leading into that we probably shouldn't have taken them. But we did and that's a mistake that I made."

In the book, he says he took both aside in the Caribbean during the series against the West Indies that directly preceded the Ashes tour and asked them: "Are you going to get some runs or are you going to retire?"

"They both said they would get some runs, but I knew in my heart of hearts they had run their race at Test level," Lehmann writes. "I admit I did allow myself to be blinded a little through sentiment and a belief they could turn around their declining form.

"Given my time again my preference as just one member of the NSP (national selection panel) would have been to look beyond Watson and Haddin for that Ashes series, but circumstances dictated otherwise. Hindsight is a wonderful thing."

Lehmann was heavily criticised over the call not to bring Haddin back into the side at Edgbaston last year when he made himself available again after sitting it out for family reasons at Lord's.

The Australian hierarchy was slammed in particular for appearing to ignore their "family first" ethos by sidelining Haddin, but with Nevill having acquitted himself well in his debut, a resounding Australian victory, Lehmann and co felt they had little choice.

Haddin had dropped England century-maker Joe Root in Cardiff and not made an impression with the bat in both innings there, leaving his spot in the side on the agenda before he missed Lord's, Lehmann said.

"In the case of Brad Haddin what it boiled down to was, first and foremost, a selection issue, as we should never have taken him to the West Indies and the United Kingdom in the first place, something I think he, too, now acknowledges.

"I thought he could continue to perform to the required level in the Caribbean and during the Ashes series but, with my experience, I should have known better."

Lehmann believes the Australians were hurt by the fact that the same squad toured both the West Indies and England and there was no time to reflect in between, and says he would try to ensure that never happened again.

The release of Lehmann's book comes in a month in which autobiographies by Clarke and Mitchell Johnson have detailed past tension within the Australian side.

"There are a lot of different books out there at the moment that are probably having a crack at everything and everyone, but for me I certainly don't want that," he said. "It's more of a coaching book than anything else, my take on coaching and hopefully encouraging people to take up coaching,"

Coach by Darren Lehmann
Penguin Random House Australia
RRP $39.99