Sousa saw his side beat Liverpool 1-0 in Switzerland in their last Group B encounter, despite being thrashed by Real Madrid in their opening European fixture this term.
It is the Reds, though, who now have to face Madrid - twice in a row.
And Sousa feels the difficulty of both ties will favour Basel when it comes to progression out of the group stages.
"They [Real Madrid] have great players. [Cristiano] Ronaldo is in fantastic form but they also have so many other players. Gareth Bale is now also a very important for them. They score lots of goals. The potential and quality is high. It will be difficult for Liverpool," he is quoted as saying by the Daily Mirror.
"They should be two fantastic matches from a football point of view. Real Madrid have a big chance to win both games. Would it help us get through? Yes but we always need to look to ourselves.
"There is a big difference between us and those clubs but we want to be competitive. That is what we managed to do against a historical team like Liverpool with great players. I am happy with what we have done and hope we can keep up this level of play."