Van der Vaart, who has scored six goals in nine Premier League games this season, suffered a hamstring injury in Netherlands' friendly draw against Switzerland last week.
Joe Jordan, deputising for manager Harry Redknapp after his heart operation, said: "We have to get Rafa from 75 per cent to 100 per cent. We'll take it day to day and we do have a few days with the game on Monday."
The international weekend also saw Manchester City striker Sergio Aguero seemingly pick up a groin problem but the Argentina star says he will be fine for Saturday's home game against Newcastle.
The big game of the weekend sees Liverpool visit Chelsea on Sunday. However, the Reds will be without Steven Gerrard.
The captain has only made five appearances this season and was recently pictured in a protective cast. Manager Kenny Dalglish has not set a return date for his talismanic midfielder.