Lehmann, the Australian team coach for five years until the cheating debacle in Cape Town, believes their international cricket bans for Steve Smith, David Warner and Cameron Bancroft should remain, but the three should now be able to play Shield cricket to sharpen their skills for 2019.

A decision by Cricket Australia this week confirmed that Steve Smith and David Warner’s 12-month ban remained until March 29, 2019.

Opener Cameron Bancroft’s nine-month ban lifts on December 29.

“The international bans I have no problem with, but it was too rushed and done too hastily,” Lehmann told a University of Queensland cricket breakfast in Brisbane on Tuesday.

“The one I have a problem with is not letting them play domestic cricket. I don’t understand that at all.

“I see they play for Randwick – those boys in Sydney - and they are getting to 3000 to 5000 coming to watch them every weekend.

“Now I can’t understand why they can’t help the state Shield system.”

Lehmann said Sheffield Shield cricketers would learn from having to play against Smith, Warner and Bancroft and crowds would come to watch matches.

“The other reason they should play state cricket is that when they come back to play for Australia their first games are a World Cup game and the first test match is the Test match of the Ashes," he said.

“You can’t expect them to play well straight away, so in effect the ban actually gets longer than 12 months.

“It goes to August or September (2019), so it almost ends up being an 18-month ban before they are back playing decent cricket.”

Lehmann was exonerated from any role in the cheating incident, in which the three players used sandpaper to roughen one side of the ball to get more swing after lunch.

He voluntarily stood down as Australian coach five days after the incident.

Lehmann told a room of 250 former cricketers he resigned because “as head coach, I have got to take responsibility for that”.

“For that I apologise for what the three lads did for 25 million people in Australia and to the 250 people here,” he said.

Lehmann told the room there was no large meeting in the Cape Town dressing room among players to decide what happened after lunch on March 24, when Bancroft was caught on camera using the sandpaper.

He said players were in different locations in a large, multi-roomed dressing room that afternoon.

"Cape Town has a couple of dressing rooms,” Lehmann said.

"There was no ‘meeting’ as such. That’s rubbish.”

Lehmann said it was not one dressing room where all the team gathered.

“You can mix and mingle and there is a lunch room out the other side and there is people out the front, then there’s people in the viewing room," he said.

“It was not like that at all. There were guys just having a quick discussion and (they) just went with it.

“It wasn’t all of us either. It was just a couple of guys having a chat and just doing it. It was disappointing that it happened like that. You wouldn’t know what they were chatting about."

Lehmann described his five years as Australia’s cricket coach as the “best job in the world” in a room that included Australia’s former Test coach John Buchanan.

“I am sad to leave that job, but I probably coached a little too long to be fair,” he said.

“You are talking 300 days away a year. If you put it in AFL or NRL terms that is 10-year NRL or AFL (coaching) career.

“You are never home, you never see your kids. It’s 24/7.

"You love it, but you are never sleeping and you are always worried about one of your blokes doing something wrong.”

Lehmann said his best memory of his coaching career was the way a shocked and tearful Australian team picked up to win the Test Match against India in Adelaide in 2014, after the death of batsman Phil Hughes.

He said Australia, which was struggling at the moment, could still beat India in Australia with its bowling attack and said it would do "better than people expected" at the World Cup in 2019.

Lehmann also outlined which team he would take to the World Cup: David Warner, Aaron Finch, Chris Lynn, Steve Smith, Glen Maxwell, Mitchell Marsh, Alex Carey, Pat Cummins, Josh Hazelwood, Mitchell Starc, Nathan Lyon, and another spinner.

“That’s not a bad one-day side," he said. "That will go alright in the World Cup.”