The midfielder fought his way back and earned a new contract in the summer and was hoping to regain a first-team spot, especially after playing well in the middle of the park opposed to his usual right wing position during pre-season.
But he has featured only twice in games this season, both as a second-half substitute against Colchester and Torquay following nearly two years on the sidelines due to a career-threatening knee injury.
Hamshaw tore a muscle during training and this will come as a blow to Turner, who could have called on him on tomorrow following Chris Marsden's probable omission from the squad because of family worries.
First-choice defensive pair Graeme Lee and Guy Branston are still missing due to injury and suspension respectively so it is expected that Richard Wood will continue in the middle with Lee Bullen while Patrick Collins stays at right-back as Wednesday look to be the first team to take points off of the flying Luton Town tomorrow at Hillsborough.
Last season the corresponding game ended in a disappointing 0-0 draw while The Owls let a two-goal lead slip in Bedfordshire to lose 3-2.
Expect Steve Howard to be a threat - the striker Wednesday wanted to pay £500,000 for in June; he has five goals in six games already this season.