Barcelona don't want to lose points now after they drew with Rayo Vallecano, because every next loss of points will give Real a reason to increase the gap. Valencia lost to Osasuna in the first match away, I think it will be even more difficult for them against Barcelona away, so yes, Barcelona should win this match. But the odds are too small for a win, so this match will be combined with other matches. But I'll probably just skip this match and see how Barcelona plays, I want to make sure that everything is okay with them.
Valencia is not a weak club, and seriously, even if Barcelona will be playing at home, they must be very active in the match since we already know how strong Valencia is, and they are not a weak team against Barcelona, so the match will be a tough one.
Although I trust Barcelona and I know they are in their best performance right now, so definitely we should be expecting a good result from them, but even with that, Valencia is also a strong team. Barcelona will want to make sure they win the game 4 days from now. Let’s wait and watch an interesting match from these two clubs.