Yup, it's really that simple
If we win and Barcelona don't lose to Olympiacos, we are guaranteed qualification. And since we won't beat Barcelona 3:0 or more, we will be guaranteed the 2nd place in the group and we can fully focus on serie A until mid February.
A win here is also important because on
December 2 and December 10 we play Napoli and Inter in serie A. The last thing we need is a must win game against Olympiacos in Greece on
December 5.