Arsenal's heroic victory over Bayern Munich in Germany on Wednesday evening was still not enough for them to reach the last eight as they followed Manchester United, Manchester City and Chelsea out of the competition.
However, while some commentators have suggested that is a reflection of the dwindling power of the Premier League, O'Neill, who led Celtic into the continent's most prestigious club competition, does not concur. He said: "I'm afraid I don't agree with that, I don't agree with the reasoning behind it, let me put it this way."
O'Neill added: "Everybody can have their own opinion about whether the league is strong or not, but if you start making judgments of a whole league simply on the back of a couple of results in the Champions League, I'm afraid I don't buy that and never have done.
"Last season, for instance, Chelsea won the Champions League from our league.
"We saw a game the other night, a fantastic game - Barcelona were absolutely magnificent in the match against AC Milan.
"However, if the ball that hit the post had gone into the net, it might have been a long way back for Barcelona.
"Just let's say hypothetically they had been beaten - would that have meant that the Italian league was stronger than the Spanish league on the evidence of that result?
"I'm afraid I don't agree with that."
- Sports & Recreation