The both players are just coming back from injuries and as you know well, getting back to full fitness ain't that easy as you think, I believe they will both be back to their best performance, their absence really affected Liverpool both as a club and as a team, but trust me them getting back to the team is gonna be a thing to look out for, it's gonna be a though season, just give them time to adapt.
RE: Van Dijk poor performance leads to Liverpool fc losing against Hertha Berlin: The talking point and the reason not to blame him