Charlton chief Bob Peeters is expecting a stern test when the Addicks host Wednesday on Saturday.
Peeters believes the Owls are a robust side but has pledged to match fire with fire at The Valley.
He said: “They are a very physical side and if we make it physical then it will be very tough for us.
“If we can play our game and pass the ball a little bit more than we have a chance. They are a strong, collective side and they are very good on set pieces.
“The Championship is a very tough competition and we think that we will be ready for Saturday.”
A familiar face at the back lies in wait for Wednesday as Charlton secured the short term signing of Oguchi Onyewu on Friday.
The USA international is eligible to feature against his former employers.
One ex-Owl who will play no part in the capital, though, is Addicks centre half Michael Morrison.
The erstwhile Wednesday stopper joined Birmingham on loan on Friday.