"I don't worry about Robin as I spoke with him two weeks ago and he made a cheery impression and expected to be back in April," Van Marwijk told a news conference at which he announced his 23-man squad for Wednesday's friendly against the United States.
Van Persie, 26, has not played since an operation on his right ankle after he was injured in a friendly international against Italy last November.
Van Marwijk said he had not been in contact with Van Persie's Premier League club Arsenal.
"I don't think that is important. It is about the player and the most important thing is that he will be fit and in good shape for the World Cup," he said.
Van Marwijk said striker Ruud Van Nistelrooy could still make the World Cup squad despite announcing his retirement from international soccer after Euro 2008.
Van Nistelrooy left Real Madrid during the January transfer window to join SV Hamburg.
"Ruud is a wise guy. He told me that he would let me know when is absolutely fit and in form," Van Marwijk said.
The Dutch will play in Group E in South Africa against Cameroon, Japan and Denmark.
Dutch squad:
Goalkeepers: Maarten Stekelenburg (Ajax Amsterdam), Michel Vorm (Utrecht), Piet Velthuizen (Vitesse Arnhem)
Defenders: John Heitinga (Everton), Joris Mathijsen (SV Hamburg), Andre Ooijer (PSV Eindhoven), Edson Braafheid (Celtic Glasgow), Gregory van der Wiel (Ajax Amsterdam), Giovanni van Bronckhorst (Feyenoord), Ron Vlaar (Feyenoord)
Midfielders: Nigel de Jong (Manchester City), Demy de Zeeuw (Ajax Amsterdam), Stijn Schaars (AZ Alkmaar), Ibrahim Afellay (PSV Eindhoven), Wesley Sneijder (Internazionale), Orlando Engelaar (PSV Eindhoven), Mark van Bommel (Bayern Munich), Rafael van der Vaart (Real Madrid)
Forwards: Dirk Kuyt (Liverpool), Arjen Robben (Bayern Munich), Klaas Jan Huntelaar (AC Milan), Eljero Elia (SV Hamburg), Ryan Babel (Liverpool).
