I see this as the biggest game of the season so far, in many ways. As GLewis says, we need to demonstrate (with actual evidence rather than talk) that we can manage a dual Prem/European season, and if we're going to be pushing towards the upper reaches of the table, we need to be beating Burnley.
We have a week to prepare for the Swansea game, which I'd expect us to win, and which would see us with 9 points from 3 games, if we can win tomorrow as well. That would see us moving into a strong position in the league, as well as being top of our EL group (all in all, that would be a pretty good start to the season).
I know it's still very early but we don't want a little gap to open up between us and the top 4/5 teams, where we are having to play catch up. Burnley will have prepared specifically for us all week long and will be really motivated to get their first win, whereas we probably only started preparing for them properly, as a full group, on Friday afternoon maybe. Important game.