Sean Dyche says he will be facing the unknown when his Burnley side host the Owls on Saturday.
The new-look Wednesday travel over the Pennines to Turf Moor as the Championship resumes following the international break.
Dyche said: “They’re carrying a very big squad of recognised first team players. They’re a new group trying to formulate as well as we are.
“We’ve got a way of working where the hardcore of our players understand that.
“They’ve got a new manager along with lots of new players.”
One name familiar to the Clarets is Ross Wallace, who departed Burnley over the summer and headed to Hillsborough.
Dyche added: “It will be good to see Ross. Other than playing against us we wish him well in his time there.
“He had some good moments for us. He didn’t play as much first team football as he probably wanted which is inevitably why in the end he’s gone, but he played some important parts and was always good around us and around the group.
“He had some really key moments in our time here in helping the team to be successful.”