It was clear since Diaz bought a large sum, that Liverpool knew that one of the two stars; Salah or Mane will leave the team.
I don't know if Liverpool would be the same team without Sadio Mane.
Klopp himself has known since the days of Dortmund that replacing stars is not a picnic, nor an equation that guarantees his success.
RE: Monitoring players future at Anfield, the official home of Liverpool fc