Crystal Palace boss Roy Hodgson admits the commitment of his off contract players is a concern.
Palace, who surrendered a lead to lose 3-1 at Southampton on Tuesday evening, have a host of first-team squad members out of contract this summer.
The 73-year-old expects his players to remain professional for the duration of their stays at Selhurst Park but acknowledges that uncertainty over their futures may be an issue.
"Yeah, there was some experience on there. But of course we can't deny the fact that there are players on the bench who are unsettled," said Hodgson.
"So in actual fact they might be experienced, but there is a question mark as to how much they're going to be prepared to die for the cause because we can only expect them to behave as human beings.
"We want the best from them, we expect them to respect their contracts and we expect them always to go out and give what they can give every time we step on the field.
"There are players out there who might be uncertain about what the future holds, and there will be players on Sunday when we play Aston Villa who will be uncertain about their futures.
"But they're doing what they're paid to do. They're contracted until such time as they get offered a new contract or move on, and all I can expect from them is to go out and be professional and do the job that we ask them to do."
