The Dutchman spoke about the team’s 3-0 win over Bournemouth and issued a fresh challenge to Darwin Nunez.
The Uruguayan striker is enjoying himself of late, netting a goal in the win on Saturday.
“If you want to be successful in different competitions we need a very good squad and now it's time when we are rotating they have to perform and today showed; Darwin scored a fantastic goal," Van Dijk said post-game.
"You see the boys who came in after being rested in midweek produced again and that's what we need, it's a sign of a very good football team. It's the start of the season so there's a lot to happen but it's a good sign.
“Any striker, on the bench or who has a lack of confidence, works their socks off to be successful. He got a chance to be the starting striker today and he worked very hard for that goal.
"He scored a very good goal but he worked hard defensively when we didn't have the ball and those are the things that we need from the whole team, whether you start or coming in.
"For him, coming into a club like Liverpool with the price tag there is always going to be pressure to produce week in, week out and he is trying to do that but it is not always that easy.
"Now it is time for him to stay calm and I think, in my opinion, he has been doing that much better and the manager is busy with him a lot and us as players and we just have to keep him close to us and keep going.
"He started but he might not start the next game and we want him to be consistent and keep doing it and doing it when he comes on and when he starts. That's the main thing, don't get dragged into the positivity and then the low of the negativity or you will be dizzy at a certain point."