Frank de Boer says he will not take risks with Wilfried Zaha as the winger begins rehabilitation on his injured knee.
Zaha suffered the problem in Crystal Palace's opening-day defeat to Huddersfield and has missed the last two matches against Liverpool and the midweek Carabao Cup success over Ipswich.
Palace boss De Boer, whose side are favourites with Sky Bet to register their first points of the season against Swansea, is unsure when the 24-year-old will be ready for a first-team return and does not want to rush him.
"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.
"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."
De Boer admits he wants to bring in reinforcements before September 1 transfer deadline, although he would not be drawn on specific names.
"We're looking very hard and if something happens you're (journalists) the first to hear it," he said.