Coleman reckons Group A, which includes Belgium, Croatia, Serbia, Scotland and Macedonia, is as tough as it could be considering Wales entered the competition as a sixth seed.
Tuesday's match in Belgium could be the last fixture of Coleman's reign, as he still has to reach an agreement with the Football Association of Wales on extending his stay the job.
Coleman said: "We talk about qualification. When was the last time a side seeded sixth qualified? We were seeded sixth this time and the expectation was that we should qualify.
"Others who were maybe involved before me said this group were going to be this, that and the other.
"But if you look at the teams we have been up against, I don't think there is a tougher group.
"There are no excuses. We have had too many defeats. Finishing fourth in the group would not be a success because it's all about qualifying.
"When I say I want to look at how I can affect things going forward, do I want to deal with unrealistic expectations?
"But I can see the reasons why I want to lead the team. I can see why anyone would want to.
"We have some very good players, and we have a chance to qualify if we can just have them all fit. But does it ever happen?
"Having had two years' experience of it I also look at that side of it and, if we are without too many players again, how can anyone do anything about it?"
But Coleman would be happy if the person who replaces him whenever he ultimately leaves his role, were to take Wales to a major finals.
"Belgium have shown this is a challenge that can be achieved," he said. "I genuinely believe we can, but I keep repeating we can only do that with certain players available more than they have been.
"We have good enough players, but they are never all available,
"If someone comes in after me and I can't do it or don't achieve qualification, I'd be happy if someone else did because I'm a proud Welshman and I want Wales to do something special.
"I'm torn, I don't want to think if we have the same scenario and have too many players missing and have unrealistic expectations, do I want that again?
"But if we have got everybody for longer, I'd love to be that man."
Injury-hit Wales face a stern task against group winners Belgium as the Red Devils prepare to celebrate their qualification for Brazil in front of a sell-out crowd at King Baudouin Stadium.
But Coleman has vowed his side will do their utmost to spoil the party, saying: "You look at Belgium's squad and it is the most expensive squad in Europe.
"Look at what players they have got, they can leave two or three out and the players they replace them with are very strong, experienced and talented.
"They have won the group at a canter and they have not done it for nothing.
"They are a top team, it doesn't matter what team they put out, it is one heck of a test, it is good for us. We are looking forward to it and relishing it. It's a good test."
Belgium v Wales is live on Sky Sports 3HD at 7.55pm