The Tykes were relegated from the Championship on Saturday with a 3-1 defeat to Middlesbrough at the Riverside Stadium.
Wilson admits that an overhaul of his squad might be needed if the team wants to gain promotion at the first attempt.
"If we are going to bounce back we have to be strong, and we have to make sure we are looking forward straight away," he is quoted as saying by Sky Sports News. "Yes it will take some getting over but we have to do it quickly.
"A clear-out might not be the right word, but there will certainly be some fresh faces and one or two players will leave, that goes without saying.
"We have to make sure when we come back for the first kick-off in August that we have got a bright and enthusiastic group of players that are determined to bounce back straight away."
Barnsley are back in action on Saturday when they play host to Queens Park Rangers.