Maybe one of the reasons for Liverpool's defeat is that they wanted to prepare for the Champions League match. The Champions League is more important and Nottingham was an opponent they did not see as strong. They must have thought that they could beat them in any way and underestimated them. But you shouldn't do that. You should take every opponent seriously, both in the league and in the Champions League. This defeat could even cost Liverpool the championship at the end of the year.
Liverpool defeat was more than just preparing for the champions league because their key players were on the pitch not on bench. So many errors from on play resulted to their defeat at Anfield. Salah as their key player in most cases was responsible for their greatness and downfall at the same time. They could have won that game if he wasn't selfish and stingy with passes.
On a two clear occasions, they will score if he had passed to his teammates instead of aiming for the goal. The couch too made his mistakes with substitution but I don't blame him too much since Liverpool lack squad depth. Salah, Trent and Szobo could have been subbed out but unfortunately there was no one to replace them. I forseen it from their first half performance hoping to see game change in the second half but nothing change. Let see what happens tomorrow when they face AC Milan.
Liverpool does not have luck in the game because they perform well, but they do not have the opportunity to score a goal, and all of the defenders move outside, while Nottingham Forest gets one chance and scores a goal, and all of the players begin defending, and Liverpool does not have the opportunity to break through their box. Forest did their best and earned three points at Anfield. Let's see how they play against Ac Milla tomorrow, but I believe Liverpool can win the match if they perform well because they are the favorites, but Ac Milla are good in the UCL because they play the competition more than Liverpool. The new coach loses their first Premier League game, no one believe that Liverpool will lose in that match,If he can win his match against Milla in the UCL. Manchester City must lose or draw in order for Liverpool to challenge them again and compete in the league table however, if Guadiola does not lose a match, Liverpool can't compete anymore and no league for them.