"It was," he said this week, "a kick in the bollocks."
Wells had won Olympic gold and silver in 1980, and was still a major force, despite nursing a hamstring injury. He assured selectors he would be ready and that, if not, he would withdraw.
Confidence in his selection was so great that he had already been sent a suitcase of kit. The selection committee - some 25 strong - decreed that he must run a trial in Belfast. "They said it was just to show I could run from A to B. So I went," Wells recalled.
The selector detailed to observe banged on the window as his bus left the stadium and told Wells he was satisfied. Days later, Mike McLean, the clearly-embarrassed chairman of the selectors, told Wells he was not in the team. "He said he'd done everything he could to persuade the selectors," Wells recalled this week. "The vote was 21-6 against, I think he said. I could barely take it in.
"I was not in the greatest shape when I went to Belfast. I worked with John Allen at Guildford. My hamsting had had a little tweak, but there was not a lot wrong. He said to make sure I got the first start, because he was not confident in a second one. John is the most pessimistic animal on God's earth. That laid a seed in my head. It was a negative which I didn't need.
"In Belfast, I was up, ready to go . . . false start. That seed was in my head and I didn't quite get the same start, second time, and I finished third - 10.43, I think. The selector said: 'Allan, I am going to put you forward to be selected. You've shown you're fit and that's fine'."
When McLean called, he told Wells the same individual had voted against him. "That's the kind of people I was up against, the kind of people I ran for, who decided whether I was selected or not. So small-minded: they do not understand what individual athletes put in to it.
"The commitment I had was undermined by people who did not understand my professionalism. Saying all that, I still had the hamstring problem. But I did a trial on the Saturday before the end of the Games at Glenrothes. I ran the fastest I ever did for both 100 and 200m. It was pretty windy. Stuart Hogg [the sprint coach] was there. There were two or three time-keepers. I ran 9.80-something and 19.90-something. It was hand timing."
A couple of days later Andy Norman, the British athletics promotions officer, invited him to run at Gateshead. Wells agreed. It was just five days after the 200m final in which Scotland had no finalist, and three days after their bronze medal in the sprint relay. It was the first appearance of lycra. The so-called Wells Wonderpants. It started a global trend.
Wells ran both the 100 and 200 metres on Tyneside, first beating Ben Johnson, Canada's newly-crowned Commonwealth 100m champion, and then 200m winner Atlee Mahorn.
Egg on the faces of the Scottish selectors? "That's exactly the same question the commentator asked me in 1986," says Wells, laughing. "Truth is, in some ways it was a relief I did not run in Edinburgh. The physical and psycholgical sides would have to come together. If selected I'd have had more people helping me, more physio on the leg - all the team back-up.
"But I did not go out to show these b*****ds, or whatever. I just went out and did what I felt I wanted to do in the best way I could. It's always a question mark, coming back from injury. But here was a bigger question mark - competing against the two guys who'd just won Commonwealth titles. It was an opportunity to make it solid in people's minds, if I'd won.
"I'm not sure Ben Johnson was happy about running. I think there was a row about him not getting enough money. So I just told the TV commentator that if they felt it's egg on their faces, so be it.
"I'd like to have run in Edinburgh. I could have been standing here with more medals from the Commonwealth Games. It was one thing that I really loved to do: run for Scotland in the Commonwealths. I could focus on fewer people. It is a lesser event than the Olympics and World Championships. You have to accept that. But I loved it."
Twenty-eight years on, the hurt, anger, pain and disappointment still fulminate. "It was a kick in the bollocks," he said. "In fact it was worse than that."
Wells was then, as he remains today, quite simply, Scotland's greatest sprinter. The manner in which he was stripped of his Scotland uniform, and even his dignity, still beggars belief. Allegations of East and West rivalries surfaced.
As Wells said: "Sometimes we are our own worst enemies . . . I was an Olympic gold medallist, had won four Commonwealth gold medals, a silver and a bronze, and they just kicked all that into touch. If I was ever in a selection situtation, you have to take into account the ability and character of the athlete and, above all, what he has done in the past.
"For me to not to be selected to run in Edinburgh, where I was born and brought up, was just unbelieveable. Even if I was not running well, I would still have picked something up. I just feel the honour and privilege for what I had done for Scotland, and being an Edinburgh person . . .
"It was probably 21 west selectors and six east - I can't remember the exact numbers; something like that - but I can't change history. I still feel that I was let down."
Wells is now a systems engineer at the University of Guildford in Surrey. A 2014 ambassador, he is confident Glasgow will be a huge success, an opinion he holds despite - nay, because of - the absence of Usain Bolt and Yohan Blake from the 100 metres final a fortnight tomorrow.
"It will be better and more exciting. It's going to be a closer-run thing. It will show who has the character: who wants to win it most. It is quite an even field and the one who really wants this most is going to come through on the line."
With no Scots selected, he foresees the English trio - Harry Aikines-Aryeetey, Richard Kilty and Adam Gemili - all making the final. "I don't see why not, and it will be more exciting. Seeing Bolt win by several yards would be boring.
"I don't think Bolt will ever run as an individual at the Games now and I don't think he will break his 100m record again. It's so difficult. I know how diffiult it is to run your personal best. To come close to that you need the right condtions, everything absolutely spot-on. And you need to want it more than ever. I think Bolt has surpassed that point, way back.
"Before the season he was quoted as saying he would break his world record at the 100. I think that's more appropriate at 100 than 200, but I don't think its going to come. I think he is gone.
"If you look at the Jamaicans in Lausanne the other day, we did not see any of them run half decent. I don't know what we are going to see from them in a fortnight."
He has mixed feelings over Dwain Chambers, with all his doping history, potentially being on the podium. "I don't think he actually ran much better when he was using drugs than he did without them. And I think he'd have been a better athlete if he'd stayed off the stuff."
Is he uneasy that Chambers is competing, or entitled to be there? "If science is suggesting you still get the benefits from drugs years later, it's difficult. But when somebody does the sentence, you have to accept them back. That's the law. I accept if someone is given a ban, does their time, they are back a couple of years later.
"But there is a moral issue when you see an athlete like that back on the track. He doesn't really count. That's how I look at it, in a way . . . you look at the guilty with a different eye. The robber does 10 years in jail. Will he come out and not steal again?"
His eyes and ears, which is how he always refered to his wife and coach, Margot, is still coaching. Yet despite marked success in several fields, she has never been pursued by athletics, despite the likes of an honorary degree from Napier University. "It was a hard road. Margot sacrificed not just her athletics, but a period of her life when she could have been doing something different.
"Her commitment to me was 100%, but sometimes I think she did not take as much pressure off me as she might have. She is playing a part now I'd like her to have played when I was an athlete. But she was under great pressure too. In Moscow she came out in a rash - she had thousands of spots on her back. I wondered if she had eaten something. But as soon as the Games were over, it was gone."
Now 62, Wells still finds it hard to let go. "You do the business on the track but your brain is still thinking through your technique. It blows through your veins: performance, competing, training. It was going through your head all the time. I miss all that. I miss that side of it because it was so stimulating for me. So inspiring. I still do miss it."