Jordan Thorniley debuted for the Owls on Saturday and impressed new manager Jos Luhukay with his performance.
The youngster was one of three centre halves slotted into a 3-5-2 formation and helped provide a firm foundation as Wednesday recorded a third clean sheet on the spin.
Luhukay said: “It was a good game for Jordan and I am happy he had this chance against a good side like Cardiff.
“He played well, he did what he had to do playing for the first time in the Championship.
“I am not afraid to play anyone if they deserve to play, it does not matter how old they are.”