Lehmann was dismissed by the Bundesliga club on April 9 this year, along with head coach Manuel Baum and technical director Stephan Schwartz.
The former Germany international, who won 61 caps for his country, was appointed by Baum in January but the management duo only oversaw three victories in their time with the club, leading to their ouster.
When they were sacked Augsburg were 15th in the table, only four points above the relegation playoff spot.
Martin Schmidt took over from Baum and staved off the threat of relegation though the club still finished in 15th place, and had the same four-point margin over Stuttgart, who occupied the relegation playoff spot.
Lehmann has spoken of his dismissal for the first time and the 49-year-old was still surprised by the manner of his dismissal.
“[Augsburg General Manager] Stefan Reuter called,” Lehmann told Bild.
“The phone call lasted ten minutes. He said: ‘We separated from Manuel Baum.’ I thought: ‘What is coming now? Sack or promotion?’”
Despite the relationship between Lehmann and Reuter from their time together at Dortmund and the national side, there was no sentiment for the retired shot-stopper.
He did believe that he’d be offered the chance to remain as an assistant, but Reuter told him that wasn’t an option.
“Actually, I did not expect the coaching job, because they stressed when I signed my contract that is wasn’t part of the deal.
“But I was told on arrival that I would stay if there was a new head coach. That’s different now.”
After he was dismissed Lehmann has had no contact with Schmidt, who will be at the helm at Augsburg in the new season.
He does believe his short time with the club was of value, despite it coming to a strange end.