Lambin has previously been on the books of Greek side Ergotelis before featuring regularly for Wednesday's development squad in recent weeks.
He is viewed as one for the future by the Championship club and has been challenged to make an impression on Dave Jones' first-team plans.
Development squad head coach Lee Bullen told the club's official website: "Khalil was identified by the staff at first-team level as one for the future.
"He's been with us for pre-season and brings a lot of energy to the team. He's a young boy and is still adapting to the British game but has performed well in pre-season.
"He has trained with the Under 21s and been involved with the first team on matchdays. He has shown he can score goals and the hope is that he can continue his development with us and make strides towards the first team."