The reason why Arsenal has fallen during Christmas was because they have been maintaining the same pattern of play for a long time which made them very predictable. Now the coach would have a different pattern to execute in the field but there are no subsequent players to use in playing them. Most of their players are on injuries. I could remember Timber, Partey, Tomiyasu, Viera and some other players were on injury quite some period. Although i heard rumours that most of them are back and are ready to play in the competitions.
Controlling the ball for too long is indeed a problem for a team because the opposing club will be very quick to understand and guess where the ball is going and it will definitely end in a bad way and who knows what the Arsenal players were thinking who were supposed to play fast but became very slow and very easy to beat. guess.
But that's not the only bad thing about Arsenal because they lack reliable players and several players are injured as you know and what I always pay attention to is that the defense line is always careless and can always provide space for their opponents.
If this is not fixed immediately, it will definitely be very difficult for Arsenal to continue trying in the CL to become a strong challenger when the match starts. Arsenal will have to face Porto, which is known for its fairly strong attack line.
Even though Porto is not a very strong club, if Arsenal performs in this way it will definitely be very difficult to play against Porto and I am a little doubtful whether Arsenal will qualify for the next round if their performance is as bad as this.