A fairly acrimonious split from Kilmarnock in June left Shiels out of work and searching for his next challenge. Coaching youth players and doing bits of media work didn't adequately fill the void. "Football is my life. I don't play golf, so I was itching to get back," he said.
Now Shiels has resurfaced at Morton, a club anchored to the foot of the SPFL Championship and with a real fight on its hands to avoid relegation. Given his achievements at Kilmarnock - a League Cup win, victories over Rangers and Celtic, bringing through a number of youth players - as well as his high profile, the expectation was that the Northern Irishman would return to the game at a higher station; another Premiership club perhaps, or a Championship side in England.
Shiels, though, is dismissive of such a suggestion, believing it to be both "derogatory and disrespectful" - presumably to Morton rather than himself. If he had any qualms at all about taking a job at a club that could very well be operating in the third tier of Scottish football next season then there was little evidence of it at his introductory press conference inside a cramped Cappielow boardroom yesterday.
On the contrary, Shiels could scarcely have been more enthusiastic and seems to have found a kindred spirit in Douglas Rae. Morton's 82-year-old chairman and benefactor nodded approvingly as his new manager reeled off a list of the people he had met since his confirmation on Friday, chattered excitedly about the club's many community programmes, and showed he had studied the history too.
"There were 266,148 people [in aggregate] at the 1948 Scottish Cup final," he revealed proudly, like a student who has been up all night cramming for an exam. "Morton were beaten by Rangers over two games. They also won the Scottish Cup in 1922. Did you know that?"
It is only common sense for any new start to sook up to their boss, but Shiels seemed genuinely intent on doing all he can to realise Rae's dream of seeing Morton back in the top division for the first time since 1988. There was no mention by name of Michael Johnston - the chairman of Kilmarnock with whom Shiels famously fell out towards the end of his tenure - but it seems, in Rae, Shiels sees a football man from the same mould as himself. He has signed just an 18-month deal as manager but insists his intentions are to hang around for the long haul.
"If I had met the chairman and he'd said he just wanted to escape relegation, it would have dissipated my interest," Shiels added. "But I feel really good about his view of where he wants the club to go. If you look at chairmen you meet throughout your life, this one is someone I feel drawn to, and now I want to do something for that guy. I want, in the later years of his life, to achieve the goals he dreams of. It isn't money which is going to make him happy, it is that goal of being at the top level of Scottish football.
"I have so much respect for that type of person who has given everything. His dream is my dream now. I've signed an 18-month contract but I feel that I'd like it to be more. I'm not here for a stepping stone. If it takes one relegation and two promotions then that's what it will take. But that's my ambition."
Shiels will spend his Morton debut against Falkirk on Saturday in the Cappielow stand, the legacy of a four-match suspension (two suspended) picked up shortly before he left Kilmarnock. There are few as outspoken and candid as Shiels in the game but he promises he returns a changed man. "I'll not be in front of the SFA [Scottish Football Association] again I can assure you of that. I was totally honest in everything I did but that's history now and this is a new chapter."
Shiels became so immersed in life at Kilmarnock - first as assistant to Mixu Paatelainen and then as manager for two years - that it left a hole in his life when he moved on. He returned to the club's training ground at 6.30am last Friday morning to achieve what the Americans call "closure" before embracing his next role.
"I fell in love with Kilmarnock, there's no question of that," he added. "When the chairman here told me I was getting the job I wanted mental closure, so I went to the training ground on Friday just to close that off from my head. It was an emotional time for me, but there is no question I will now fall in love with this club and the people.
"What that does for you as an individual is it gives you a drive and commitment to go and work for that club. I don't know how anybody can manage a football club without being in love with it."