What worried me about our game at City (don't worry it's Havertz related) was when I saw that they started with 2 holding midfielders (Gundogan & Rodri). I said to my brother that I hoped we didn't "fall for this" as it was obvious that Guardiola is learning how to play against us. Instead of City bombing forward they played on the back foot (a bit like we do to great effect in Europe) and tried to hit us on the break. Unfortunately we didn't read their intent and we duly attacked them and played right into their hands. They only had 4 attacking players on the pitch (Foden, Jesus, DeBruyne and Sterling) which is very rare. However 4 was enough especially when you have DeBruyne pulling the strings.
Teams have cottoned on to us and play deep. Fortunately our front 3 are usually good enough to undo these tactics.
But recently, against the better teams (City, Napoli, Atletico) our front 3 have largely been nullified.
Our midfield is very good and Hendo, Milner, Fabinho, Ox, Gini etc are all very good players BUT we don't have a midfielder who can beat a player for pace/skill like a Coutinho, Havertz, etc or can unlock a defence with one pass like DeBruyne.
I am sure Klopp was hoping that Keita would be that player but as yet he hasn't shown he's up to the task consistently. The difference Havertz would make would IMO take this squad to the next level. The option to go to the toughest away venues and play Havertz behind Salah, Mane and Firmino whilst leaving the other 6 players sitting deep is most appealing.
Also, at 21 FSG would hopefully look at his signing as an investment i.e. his value will continue to rise for at least the next 4 or 5 years.
I know it's very unlikely that we are gonna spend big but IMO we need someone like him next season if we are to win major trophies.