Maciej Szczesny - who won seven caps for Poland - says Wenger must take responsibility for his son's form slide.
He told Przeglad Sportowy: "Wenger already started to look for the scapegoat. It is not the way the boss should behave.
"Wojciech has had two serious injuries. He played with one in April and May (last year). He shouldn't have agreed to play that time, but the coach insisted.
"Wojciech did not train the whole week and then a warm up on Friday and played the match on Saturday. He was naturally more susceptible to minor injuries and his form was going down.
"Wenger was playing with the young man's good health and Wojciech agreed foolishly.
"In my opinion Mr Wenger messed up a lot in April and May. I don't blame the young man who went along with his coach, his current lack of form is a result of those two months.
"Then in August there was a foot (ankle) injury after which he played almost instantly.
"After seven weeks out Wojciech trained for just seven days and played the match. How on earth can he be on his highest form?"