"Wilf is a very robust player, the first couple of days (after the injury) are very important to have a rest and, from now on, I think he's going to start rehab," De Boer said after Wednesday's 2-1 win over Ipswich Town in the League Cup.
"We don't know how long it will take. The risk is that you start too early, that he can have a setback, so we are going to see and don't put a time on it right now."
Palace, who will play Huddersfield Town again in the third round of the League Cup in September, host Swansea City in the league on Saturday.
News that makes sense
Your trusted source for staying up-to-date with the world around you. Get free daily news updates and analysis, straight to your inbox.
(Reporting by Aditi Prakash in Bengaluru; Editing by Peter Rutherford)
