Indeed, Barcelona's performance wasn't ruined by today's draw, proving they were still capable of avoiding defeat despite the pressure throughout the match. Barcelona now trails La Liga leaders Bilbao and Real Madrid by two points, but that's only temporary as the league is only in its week 3. Barcelona tried their best today, but failed to convert several scoring chances including one by Dani Olmo. I don't see that as a major issue, there's still plenty of time to see them comeback and take the lead.
Lamine Yamal opened the match with a penalty for Barcelona but they had a hard match and almost lost it. Only luckiness can help them to secure one point at the end and they already fell behind Real Madrid with 2 points less after this draw. This draw is very disappointed for Barcelona and it shows their weakness which need to be strengthened in coming matches.
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.