The Parkhead outfit have entered Europe's premier cup competition a round earlier than in previous years due to Scotland's faltering coefficient, and will begin their 2013-14 campaign against Cliftonville on Wednesday.
But, ahead of the first-leg clash with the Northern Irish champions at Solitude, Lennon has described the move as "baffling".
"I think it is really harsh to have to play an extra qualifier this year. We are the champions of our country, we reached the last 16 of the Champions League last season," he said.
"Surely there should be some sort of dispensation for clubs who do well the previous season. Maybe it is just me being selfish, but I think it is very harsh on us to be playing so early.
"I don't think it's fair considering the season we had and the amount of games that we had. To come back early for this qualifier does not seem right - we could be out by next week.
"I suppose that's the rules, the way it is set up, and you have to accept that, but baffling is a good word to use. I don't think it is right we're playing an important competitive game two weeks into pre-season."
Celtic were eliminated from the 2012-13 Champions League by virtue of a 5-0 aggregate defeat to Italian champions Juventus in the round of 16.
