The Norwegian has confirmed that he will leave the Scottish Premiership champions at the end of the season.
The Hoops boss announced a few days after the club's Scottish Cup semi-final defeat to their Old Firm rivals that he would be leaving the club at the end of the season.
But Arne Deila has seemingly quashed the suggestion that his son decided to quit solely because of the Hampden Park defeat to the Scottish Championship side by admitting that his future has been on his mind for some time.
"I'd rather not tell you about everything we discussed but I feel sorry for him. I could see it in his face, his expressions lately have not been right," he told the Record.
"It was his decision to go. He told me some time ago he had thought about it. A couple of weeks ago at least anyway."
While the Bhoys' struggles to reach expectations in every competition other than the Scottish Premiership made the decision seem almost inevitable, there was perhaps no perfect time for the announcement to be made.
Had Deila announced the decision a couple of weeks ago, it would have overshadowed the semi-final and may have scuppered their chances of taking control of the title race.
And while the end of the season may have seemed like the best option, the fairly quick turnaround to the Champions League qualifiers would have given the club a less than ideal amount of time to appoint a new manager and give the new man the chance to work with the squad before the new season begins.
So with an eight-point advantage in the league, it was perhaps the best time for Deila to announce his departure. But if they go on to squander their advantage over Aberdeen, then many may reflect on the timing of the announcement as a key reason.