Barcelona is unbeaten in its last 6 meetings against Espanyol, but Barcelona lost 6 points from those 6 matches due to 3 draws. This means that Barcelona still has the potential to lose points in this match if Espanyol plays well, but considering that Barcelona is in their best form, a win is more likely to be expected. After all, this is a home game for Barcelona and they should be well motivated to secure another 3 points to be 9 points ahead of Real Madrid.
I also checked Barcelona vs Espanyol head to head stats. I have never seen Barcelona lose a match. However, Barcelona shared the points in several matches. Barcelona and Espanyol have shared points in maybe two of the last 5 matches. Hansi Flick will definitely not want to lose points in the next match. Barcelona are in very good form. At the moment, Hansi Flick will certainly not want to drop points against a small team like Espanyol. Barcelona will definitely try to win this match by a big margin as well. Espanyol's defense is weak. Hansi FLick will want to make full use of this opportunity.
Especially for the home match against Espanyol, I think Hansi Flick was forced to rotate several players to keep them fit for the busy schedule. Barcelona has played 3 matches from 20 October to 26 October, while Barcelona has 3 matches between 3 November to 10 November. Lamine Yamal, Raphinha and Lewandowski could be rested, but not all three at once.
I don't think Hansi Flick will rest any key player in his squad for this match. Hansi Flick did not include Yamal and Raphinha in his starting XI for the match against Osasuna. Barcelona were defeated in this match. Will Hansi Flick make the same mistake again? Espanyol are relatively weak team but I think Barcelona will play with their best XI.