Both sides have collected seven points from their opening four games of the competition and will now meet at Stamford Bridge for the biggest showdown in Europe this week.
Chelsea have not been beaten at Stamford Bridge in any European group stage/league phase since 2019 and Maresca will aim to continue that record against the La Liga giants.
When will Palmer return?
Maresca first spoke on Cole Palmer, who he says will return to the pitch very soon.
“Yeah, we don't know when but for sure, it will be soon. He is already on the pitch, touching the ball and the feeling is good.
“We are here for tomorrow's game and after that we will see about the Arsenal game.
“The last time I spoke with Cole was after the session yesterday to see how he was feeling. But I didn't ask him details about the injury at all.”
Barcelona pose a huge threat
Next, Maresca moved on to the danger of Barcelona striker Robert Lewandowski, who will be one of many dangers on Tuesday night.
"For sure he is a fantastic player. He has shown all his life that he does the most important thing in football, score goals.
"We are going to try and defend as a team, be aggressive, like we always defend. But they have so many players; Lamine Yamal, Fermin, Frenkie de Jong. But we are going to try and win the game."
Can Estevao be compared to Yamal?
Chelsea forward Estevao has been in fine form this season, leading the Blues attack at just 18 years old, Maresca was asked about comparisons to Lamine Yamal which he says he is happy to see.
"Estevao is already playing at a high level. He is starting for Brazil. He is very young and for sure he can do many things better.
"We are very happy with him. It's nice for people who love football to watch Estevao and Lamine Yamal and Pedri. This is the beauty of football. We are happy Estevao is with us, and hopefully he is going to do well.
"Estevao is going to be an important player in the future, no doubt, but he has to enjoy football, be happy, and not think about being better than one player. For sure, he is going to be a top player for this club."
Would Maresca ever manage Barcelona?
Questions then turned to whether Maresca would ever manage Barcelona and his goal against Barcelona in Super Cup final win back in 2006.
"As a player it was an important moment. It was the easiest goal of my life. We were winning 2-0, the penalty was in the 90th minute and there were six extra minutes. Nice feeling, but it's a completely different thing now. They are an unbelievable team but we will do our best to win the game.
"You know me because you are always in my press conferences, whenever you ask me what is happening in the future, I always talk about how I'm happy to be here."
Is tiki-taka out of style?
Finally, Maresca was asked if the tiki-taka style of football going out of fashion as teams focus on set pieces instead.
"I don't know. I decide to be a manager because of a Pep team, Barcelona, years ago. If clubs or teams decide with a different style. I've said many times: any team can decide the way they want to play.
"I chose mine years ago and this will be the way I like to watch my team playing football and in the future. I don't think no one can be compared to that Barcelona, to Pep, because I think they changed football in Spain, where every club was trying to play in that way and then Pep moved to Germany, and everyone was trying to play that way in Germany.
"I think Pep came in England, and many clubs tried to do something similar and also England in terms of the international team."