While I was not expecting to see Barcelona lose this match they lost and even after Yamal got injured he wanted to stay in the team.
Now it seems he is going to be absent in the important match they are going to have with Atletico Mardid, and this can make everything harder for Flick and his players because Atletico Madrid is going to be a much harder competitor for Barcelona than Leganés.

This will be a big disaster for Barcelona, considering that Lamine Yamal is still the backbone of the attack in the front line. Against Atletico Madrid will not be easy, especially since Atletico Madrid has never lost in the last 6 matches in La Liga. This will further motivate Diego Simeone troops to continue to extend their consistency + tickets to the top of the standings.
Flick will not be seen on the sidelines in the next match against Atletico and still the expectation is that they will be able to maintain the top spot. As the favorites Barcelona will be under a lot of pressure and the fans of both teams will enjoy the fight for points. However, I am hopeful that Barca will give their best and I will bet on them. Yamal is in the front line of attack and the expectations were sky high for the Barca team but he may have to be out for a few weeks due to an ankle injury and it could be disastrous for Barca. The team's loss against Leganes and Yamal's injury combined make the match against Atletico a very tough test for Barcelona. His 6 goals and 11 assists this season have kept him in great form. Both teams are in the same position in the title race and the next match will determine which team will go to the top again.