Injury worry for van der Vaart
Van der Vaart damaged his ankle in a training-ground collision with team-mate Wesley Sneijder on Saturday, which prompted fears he could miss out on the trip to Portugal.
A more considered opinion from within the Amsterdam club suggests he will be fit to play in around a fortnight.
However, nothing will be decided until a scan is undertaken on Monday.
Van der Vaart missed the 5-0 win over Zwolle on Sunday and is expected to sit out what is likely to be Ajax's title clinching game against NAC Breda next week.
Despite the player suggesting he will be fit for this summer's Portugal spectacular, Oranje coach Dick Advocaat is sure to be on tenterhooks waiting for the results of van der Vaart's scans.