Carvalhal will analyse his Liberty Stadium squad at Watford and in Tuesday's clash with Tottenham before deciding who will be a part of his future in South Wales.
“The first step is to try to give confidence to the players and give them the opportunity to show what they can do," he said.
“If we change things and the answer is not what we expect, then after this we will try to improve the team in January.
“The clock is ticking, that's absolutely correct, but we can't do anything until January 1. So we have to try to give confidence to the players that are here first.
“They need to show commitment and after that we will take decisions. We have talked about the possibility of bringing in players if we need it. The chairman was open about that, but let's see the weaknesses in the team first. It's very early to talk about transfers."