What happens if you free hit and a player drops in price?

I don't plan on free hitting this week but what happens if you activate your free hit now and use your full team value to get your free hit team for this week but then at some point during the week a player loses value in your normal team?

Do you only lose the value if you make changes to your free hit team? Does it not matter until the week after when your team reverts back to normal? Or any other option?