Liverpool have taken just nine points from their first six matches of the Premier League season, their worst return since Jurgen Klopp took charge in 2015.
Postponements following the death of Queen Elizabeth II mean Liverpool have not played a domestic game since September 3, though they clinched a much-needed Champions League victory over Ajax last time out.
While Van Dijk has been an ever-present for the Reds this season, he has not always lived up to his reputation as steady defensive influence, most notably in a 4-1 thrashing at Napoli.
Speaking after the Netherlands posted a 2-0 Nations League win over Poland on Thursday, Van Dijk admitted he has been disappointed with his own displays.
"I know I could have done better in the beginning of the season. I'm not naive about that. I know very well when I make mistakes," Van Dijk said.
"I also know that I am one of the important players at the club and of course also here at the national team. I feel that responsibility.
"Mentally it's a challenge. You feel a lot of pressure on your head. A lot of people forget that too, it's not easy to do that.
"We all try to show our best and if, in my case, you are one of the mainstays at the club, then you get the criticism you deserve. You have to deal with that and that is not always easy. But I did that just fine."
The Netherlands conclude their Nations League campaign against Belgium on Sunday, with Louis van Gaal's team needing to avoid defeat if they are to secure top spot in Group A4.