Nouioui spent most of his time chasing the ball when he played in the Nou Camp for Deportivo La Coruna, but says Celtic shouldn't be fearful of the Spanish side.
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.
"No," he laughed. "Obviously not. 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."
Lassad's move to the Parkhead club has been shrouded in controversy but he stressed that at no point did he agree to join Levante.
The Spaniards claimed the player reneged on a deal to join them and insist they have documentation to back up their claim, which they say has left them considering legal action.
Lassad insisted he was not worried about any possible legal challenge to the move, claiming the confusion was down to an agent with whom he had worked in the past, but no longer.
"At no point did I have any agreement with Levante to become one of their players," he said.
"What happened was that Levante got in touch with a French agent of mine just before the deadline but I was already in touch with Celtic and decided to sign for them.
"At no point did I have any close contact with Levante so I am not worried by this at all.
"Whatever happened happened between the agent and the club, not with me directly.
"I have never ever signed any piece of paper from Levante.
"I have all due respect for this club, I played in Spain for long enough and I am well respected in Spain so I have no problem with what happened."
Asked whether the French agent was still working for him, Lassad said: "No, he is no longer my agent.
"I have worked with him in the past but this agent had nothing to do with the dealings with Celtic."
Source: team talk
Source: team talk