The Sydney premiership defender was the first high-profile assistant coach to lose his job amid the financial crunch that has forced clubs to slash costs in football department spending due to the suspension of the 2020 AFL season caused by the COVID-19 pandemic.
Told he wouldn't be re-contracted for 2021, Mattner mulled over a range of possibilities presented to him by the Crows for the rest of this year before opting for a mutual agreement and compensation that leaves destiny in his own hands.
"It wasn't the decision I wanted to make, I didn't want to be in this position, but I believe for myself and my family that the decision I made was the best one going forward," Mattner said.
"I don't have anything to go to, but, the other thing was, I'm not going to have a job whenever this season ends.
"The decision in the end was, 'Do I leave now and have clarity for what my next few months look like?' And now I can move on, get on the front foot, and put my name out and try and find something else."