Sigurdsson is a target for Everton and the Swans are holding out for a £50million fee for the midfielder.
Clement feels Sigurdsson will probably depart the club before the transfer window closes, and as such he won't take any risks with the Iceland international.
"The Gylfi situation is a crucial part of the business we could potentially do because it is going to be a high fee if he goes," he said.
"We have to make sure that if a player of his ability leaves, we have to get one or two very good players. It is not just a matter of getting two players who sit on the bench, we want quality. They have a value, they are not cheap.
"The big thing about getting the right calculation is we can spend that money on good quality players. If he stays, we have a very good player already."
The Swans will also be without Ki Sung-yueng, Nathan Dyer and Fernando Llorente due to injury but midfielder Roque Mesa and forward Tammy Abraham could make their debuts.