Considering a draw is more likely for this clash though it looks like Sevilla have the upper hand based on this season's stats.
Barcelona is indeed in a very unstable condition after last season with quite a lot of important players like Messi, Griezmann and Suarez. They've had to fight their way back into the top flight in a string of match, but it's hard to put them on the forehead. Sevilla have a good chance of winning and probably won't concede, but still a draw is a safe option.