Apparently, many bettors think like you and bet on Barcelona - the chances of it winning have changed 1.85 > 1.82 and will most likely fall even more by the beginning of the game. But as you correctly pointed out, Sevilla will have extra motivation against Barcelona, which are at least still a big name, so they will probably play much better than in their previous matches.
Barcelona's chances of winning will certainly be greater. many would bet on Barca's victory. but the betting odds seem to be getting smaller. I wouldn't bet for a big amount.
as already said, there is a possibility that Sevilla will give a surprise. they play at home and of course want to get their first win of the season.
or maybe make two bets for this match. will the odds offer to allow that? a draw or even a win for Sevilla?
The more bets are placed on a certain outcome, the less the odds become. This is the usual algorithm by which bookmakers regulate their risks.
Sevilla or draw is now listed as 1.91. You can make one bet on this outcome or two bets on two different events 1. Sevilla win 4.5 and 2. draw 3.6.