The Hoops take on Northern Irish champions Cliftonville at their Solitude base on Wednesday night in a second qualifying round first-leg clash.
But Lennon believes sides like his who have reached the latter stages of the continent's top competition should be spared an early return to action the following season.
Celtic stunned Barcelona with a 2-1 win at Parkhead on their way to a last-16 meeting with Juventus, in which the Hoops crashed out to the Italians after a 5-0 aggregate defeat.
Lennon told various newspapers: "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.
"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."