The next match is against Valencia, where Barcelona will clearly have to give their all and not drop any points. They should win the home game, which will provide further motivation to rebuild the players' morale. The match against Rayo Vallecano will certainly be tiring, but I think Barcelona will pick up all 3 points in Week 4.
In this season, with appearance of Xabi Alonso in Real Madrid and his potential ability to improve Real Madrid considerably, Barcelona will face with bigger challenge from Real Madrid in La Liga. Therefore, every match in this season with whatever opponent is truly important for Barcelona. They must to earn maximum points as possible and avoid dropped points as least as possible. Real Madrid with Xabi Alonso management will be able to take advantage of dropped points from Barcelona to take over La Liga title.
For me, competition for the title is still too early. Real Madrid are able to win three times and Barcelona are only able to win 2 times and 1 draw.
There is a difference of 2 points that may still be a change for the position of the class.
Both Real Madrid and Barcelona, I think the two teams that are trained by the great coach still carry the full target points in every game they play, especially in La Liga. It's just that when one of them does not get full points, it does not mean they underestimate the team they face like Barcelona who have to settle for sharing points at Round 3 La Liga.