This. Klopp is wedded to a 4-3-3 with a false 9 and two wide forwards. You take one of those wide forwards out of the equation, and our attack loses a significant amount of its potency.
It does look like Minamino will be a nice understudy for the false 9 role to Firmino, but there's really nobody in the squad who can deputise for Mane or Salah. Origi is pretty agricultural out wide, Shaqiri is perma-injured, and Elliott is a kid.
The idea behind Werner would've been to have some flexibility in formation i.e. switching to a 4-2-3-1 formation, and retaining pace up front even in the absence of Mane and Salah.
Klopp & Edwards need to think hard about bringing another pacy attacker in this summer. If that means selling Shaq, Wilson and Grujic, so be it. We can't challenge for much longer relying on just 2 pacy attackers in the entire squad.
I could easily be wrong but wasn't his Dortmund team more 4-2-3-1 than 4-3-3? If so seems strange he's so completely wedded to 4-3-3.