Neil Lennon's side were drawn against Barca, Benfica and Spartak Moscow in Group G and the Tunisia striker, who signed a two-year deal with Celtic at the weekend, will make a quick return with his new side to Spain next month.
Speaking through an interpreter at Parkhead, the 26-year-old, who left Deportivo at the end of last season, was asked - with a view to assessing Celtic's Nou Camp prospects - if he had enjoyed any success in the Catalan capital. He laughed: "No, obviously not."
He continued: "In the last three or four years there hasn't been many teams who have actually won, apart from Real Madrid - but it is not impossible. Everybody knows Barcelona is one of the top clubs in Europe but I do think we have a chance. It is possible to do something.
"It is extremely difficult to play against them because basically you spend most of the game chasing the ball. You run, run, run so it is very tiring.
"Playing against Barcelona has to be a good memory, whatever happens, but it is difficult, no doubt about it."
Lassad, though, denied the prospect of Champions League football was the primary reason why he decided to snub Spanish side Levante and come to Scotland, citing the possibility of winning "trophies and medals" among other reasons for his decision.
"Not specifically for the Champions League," he said, when asked if that had been the main attraction. Of course it is interesting and attractive to play in the Champions League but that was not the main thing.
"The main thing was to move to a different country and try a different league and also to play for Celtic, which is a big challenge with a big club.
"Part of being a professional footballer is to adapt to different styles. The type of football played in La Liga is different to the type played here, of course, but I am convinced I will be able to adapt."
Source: PA
Source: PA